diff --git a/swh/deposit/api/common.py b/swh/deposit/api/common.py
--- a/swh/deposit/api/common.py
+++ b/swh/deposit/api/common.py
@@ -28,6 +28,7 @@
 from swh.deposit.api.converters import convert_status_detail
 from swh.deposit.auth import HasDepositPermission, KeycloakBasicAuthentication
 from swh.deposit.models import Deposit
+from swh.deposit.parsers import parse_xml
 from swh.deposit.utils import NAMESPACES, compute_metadata_context
 from swh.model import hashutil
 from swh.model.model import (
@@ -53,7 +54,6 @@
     DEPOSIT_STATUS_PARTIAL,
     EDIT_IRI,
     EM_IRI,
-    METADATA_KEY,
     METADATA_TYPE,
     RAW_METADATA_KEY,
     SE_IRI,
@@ -74,7 +74,6 @@
     ParserError,
 )
 from ..models import DepositClient, DepositCollection, DepositRequest
-from ..parsers import parse_xml
 from ..utils import (
     extended_swhid_from_qualified,
     parse_swh_deposit_origin,
@@ -319,15 +318,11 @@
             )
             deposit_request.save()
 
-        metadata = deposit_request_data.get(METADATA_KEY)
-        if metadata:
-            # TODO: remove non-raw metadata? we don't use these anymore except in
-            # manual queries to the deposit DB
-            raw_metadata = deposit_request_data[RAW_METADATA_KEY]
+        raw_metadata = deposit_request_data.get(RAW_METADATA_KEY)
+        if raw_metadata:
             deposit_request = DepositRequest(
                 type=METADATA_TYPE,
                 deposit=deposit,
-                metadata=metadata,
                 raw_metadata=raw_metadata.decode("utf-8"),
             )
             deposit_request.save()
@@ -505,9 +500,7 @@
             archive=filehandler.name,
         )
 
-    def _read_metadata(
-        self, metadata_stream
-    ) -> Tuple[bytes, Dict[str, Any], ElementTree.Element]:
+    def _read_metadata(self, metadata_stream) -> Tuple[bytes, ElementTree.Element]:
         """
         Given a metadata stream, reads the metadata and returns the metadata in three
         forms:
@@ -517,11 +510,8 @@
         * parsed as ElementTree, to extract information immediately
         """
         raw_metadata = metadata_stream.read()
-        metadata_dict = parse_xml(raw_metadata)
-        metadata_tree = ElementTree.fromstring(raw_metadata)
-        # TODO: remove metadata_dict? we don't use it anymore, except in manual
-        # queries to the deposit DB
-        return raw_metadata, metadata_dict, metadata_tree
+        metadata_tree = parse_xml(raw_metadata)
+        return raw_metadata, metadata_tree
 
     def _multipart_upload(
         self,
@@ -608,7 +598,7 @@
         self._check_file_md5sum(filehandler, headers.content_md5sum)
 
         try:
-            raw_metadata, metadata_dict, metadata_tree = self._read_metadata(
+            raw_metadata, metadata_tree = self._read_metadata(
                 data["application/atom+xml"]
             )
         except ParserError:
@@ -627,7 +617,6 @@
         )
         deposit_request_data = {
             ARCHIVE_KEY: filehandler,
-            METADATA_KEY: metadata_dict,
             RAW_METADATA_KEY: raw_metadata,
         }
         self._deposit_request_put(
@@ -646,7 +635,6 @@
         self,
         deposit: Deposit,
         swhid_reference: Union[str, QualifiedSWHID],
-        metadata_dict: Dict,
         metadata_tree: ElementTree.Element,
         raw_metadata: bytes,
         deposit_origin: Optional[str] = None,
@@ -663,8 +651,6 @@
         Args:
             deposit: Deposit reference
             swhid_reference: The swhid or the origin to attach metadata information to
-            metadata_dict: Full dict of metadata for storage in the deposit DB as jsonb
-              (parsed out of raw_metadata)
             metadata_tree: Full element tree of metadata to check for validity
               (parsed out of raw_metadata)
             raw_metadata: The actual raw metadata to send in the storage metadata
@@ -696,7 +682,6 @@
 
         # replace metadata within the deposit backend
         deposit_request_data = {
-            METADATA_KEY: metadata_dict,
             RAW_METADATA_KEY: raw_metadata,
         }
 
@@ -839,9 +824,7 @@
             )
 
         try:
-            raw_metadata, metadata_dict, metadata_tree = self._read_metadata(
-                metadata_stream
-            )
+            raw_metadata, metadata_tree = self._read_metadata(metadata_stream)
         except ParserError:
             raise DepositError(
                 BAD_REQUEST,
@@ -850,7 +833,7 @@
                 "Please ensure your metadata file is correctly formatted.",
             )
 
-        if metadata_dict is None:
+        if len(metadata_tree) == 0:
             raise DepositError(
                 BAD_REQUEST, empty_atom_entry_summary, empty_atom_entry_desc
             )
@@ -878,7 +861,7 @@
         if swhid_ref is not None:
             deposit.save()  # We need a deposit id
             target_swhid, depo, depo_request = self._store_metadata_deposit(
-                deposit, swhid_ref, metadata_dict, metadata_tree, raw_metadata
+                deposit, swhid_ref, metadata_tree, raw_metadata
             )
 
             deposit.status = DEPOSIT_STATUS_LOAD_SUCCESS
@@ -902,7 +885,7 @@
 
         self._deposit_request_put(
             deposit,
-            {METADATA_KEY: metadata_dict, RAW_METADATA_KEY: raw_metadata},
+            {RAW_METADATA_KEY: raw_metadata},
             replace_metadata,
             replace_archives,
         )
diff --git a/swh/deposit/api/edit.py b/swh/deposit/api/edit.py
--- a/swh/deposit/api/edit.py
+++ b/swh/deposit/api/edit.py
@@ -108,9 +108,7 @@
             )
 
         try:
-            raw_metadata, metadata_dict, metadata_tree = self._read_metadata(
-                request.data
-            )
+            raw_metadata, metadata_tree = self._read_metadata(request.data)
         except ParserError:
             raise DepositError(
                 BAD_REQUEST,
@@ -119,7 +117,7 @@
                 "Please ensure your metadata file is correctly formatted.",
             )
 
-        if not metadata_dict:
+        if len(metadata_tree) == 0:
             raise DepositError(
                 BAD_REQUEST,
                 "Empty body request is not supported",
@@ -130,7 +128,6 @@
         _, deposit, deposit_request = self._store_metadata_deposit(
             deposit,
             QualifiedSWHID.from_string(swhid),
-            metadata_dict,
             metadata_tree,
             raw_metadata,
             deposit.origin_url,
diff --git a/swh/deposit/cli/client.py b/swh/deposit/cli/client.py
--- a/swh/deposit/cli/client.py
+++ b/swh/deposit/cli/client.py
@@ -19,6 +19,7 @@
 import click
 
 from swh.deposit.cli import deposit
+from swh.deposit.utils import NAMESPACES
 
 logger = logging.getLogger(__name__)
 
@@ -160,10 +161,9 @@
     if "error" in sd_content:
         msg = sd_content["error"]
         raise InputError(f"Service document retrieval: {msg}")
-    collection = sd_content["app:service"]["app:workspace"]["app:collection"][
-        "sword:name"
-    ]
-    return collection
+    return sd_content.findtext(
+        "app:workspace/app:collection/sword:name", namespaces=NAMESPACES
+    )
 
 
 def client_command_parse_input(
diff --git a/swh/deposit/client.py b/swh/deposit/client.py
--- a/swh/deposit/client.py
+++ b/swh/deposit/client.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2017-2021  The Software Heritage developers
+# Copyright (C) 2017-2022  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
@@ -10,9 +10,10 @@
 import hashlib
 import logging
 import os
-from typing import Any, Dict, Optional, Tuple
+from typing import Any, Dict, List, Optional, Tuple
 from urllib.parse import urljoin
 import warnings
+from xml.etree import ElementTree
 
 import requests
 from requests import Response
@@ -20,7 +21,7 @@
 
 from swh.core.config import load_from_envvar
 from swh.deposit import __version__ as swh_deposit_version
-from swh.deposit.utils import parse_xml
+from swh.deposit.utils import NAMESPACES
 
 logger = logging.getLogger(__name__)
 
@@ -303,12 +304,13 @@
                 'detail': Some more detail about the error if any
 
         """
-        data = parse_xml(xml_content)
-        sword_error = data["sword:error"]
+        data = ElementTree.fromstring(xml_content)
         return {
-            "summary": sword_error["atom:summary"],
-            "detail": sword_error.get("detail", ""),
-            "sword:verboseDescription": sword_error.get("sword:verboseDescription", ""),
+            "summary": data.findtext("atom:summary", namespaces=NAMESPACES),
+            "detail": data.findtext("detail", "", namespaces=NAMESPACES).strip(),
+            "sword:verboseDescription": data.findtext(
+                "sword:verboseDescription", "", namespaces=NAMESPACES
+            ).strip(),
         }
 
     def do_execute(self, method: str, url: str, info: Dict, **kwargs) -> Response:
@@ -397,7 +399,44 @@
         """Parse service document's success response.
 
         """
-        return parse_xml(xml_content)
+        namespaces = dict(NAMESPACES)
+        namespaces["dcterms"] = namespaces.pop("dc")  # for backward compatibility
+        single_keys = [
+            "atom:title",
+            "sword:collectionPolicy",
+            "dcterms:abstract",
+            "sword:treatment",
+            "sword:mediation",
+            "sword:metadataRelevantHeader",
+            "sword:service",
+            "sword:name",
+        ]
+        multi_keys = [
+            "app:accept",
+            "sword:acceptPackaging",
+        ]
+        data = ElementTree.fromstring(xml_content)
+        workspace: List[Dict[str, Any]] = [
+            {
+                "app:collection": {
+                    **{
+                        key: collection.findtext(key, namespaces=namespaces)
+                        for key in single_keys
+                    },
+                    **{
+                        key: [
+                            elt.text
+                            for elt in collection.findall(key, namespaces=namespaces)
+                        ]
+                        for key in multi_keys
+                    },
+                }
+            }
+            for collection in data.findall(
+                "app:workspace/app:collection", namespaces=namespaces
+            )
+        ]
+        return {"app:service": {"app:workspace": workspace}}
 
     def parse_result_error(self, xml_content: str) -> Dict[str, Any]:
         result = super().parse_result_error(xml_content)
@@ -434,7 +473,7 @@
         """Given an xml content as string, returns a deposit dict.
 
         """
-        data = parse_xml(xml_content)
+        data = ElementTree.fromstring(xml_content)
         keys = [
             "deposit_id",
             "deposit_status",
@@ -443,7 +482,7 @@
             "deposit_swh_id_context",
             "deposit_external_id",
         ]
-        return {key: data.get("swh:" + key) for key in keys}
+        return {key: data.findtext("swh:" + key, namespaces=NAMESPACES) for key in keys}
 
 
 class CollectionListDepositClient(BaseDepositClient):
@@ -481,8 +520,8 @@
         """
         link_header = headers.get("Link", "") if headers else ""
         links = parse_header_links(link_header)
-        data = parse_xml(xml_content)["atom:feed"]
-        total_result = data.get("swh:count", 0)
+        data = ElementTree.fromstring(xml_content)
+        total_result = data.findtext("swh:count", "0", namespaces=NAMESPACES).strip()
         keys = [
             "id",
             "reception_date",
@@ -494,13 +533,12 @@
             "swhid_context",
             "origin_url",
         ]
-        entries_ = data.get("atom:entry", [])
-        entries = [entries_] if isinstance(entries_, dict) else entries_
+        entries = data.findall("atom:entry", namespaces=NAMESPACES)
         deposits_d = [
             {
-                key: deposit.get(f"swh:{key}")
+                key: deposit.findtext(f"swh:{key}", namespaces=NAMESPACES)
                 for key in keys
-                if deposit.get(f"swh:{key}") is not None
+                if deposit.find(f"swh:{key}", namespaces=NAMESPACES) is not None
             }
             for deposit in entries
         ]
@@ -538,14 +576,14 @@
         """Given an xml content as string, returns a deposit dict.
 
         """
-        data = parse_xml(xml_content)
+        data = ElementTree.fromstring(xml_content)
         keys = [
             "deposit_id",
             "deposit_status",
             "deposit_status_detail",
             "deposit_date",
         ]
-        return {key: data.get("swh:" + key) for key in keys}
+        return {key: data.findtext("swh:" + key, namespaces=NAMESPACES) for key in keys}
 
     def compute_headers(self, info: Dict[str, Any]) -> Dict[str, Any]:
         return info
@@ -648,13 +686,13 @@
         """Given an xml content as string, returns a deposit dict.
 
         """
-        data = parse_xml(xml_content)
+        data = ElementTree.fromstring(xml_content)
         keys = [
             "deposit_id",
             "deposit_status",
             "deposit_date",
         ]
-        return {key: data.get("swh:" + key) for key in keys}
+        return {key: data.findtext("swh:" + key, namespaces=NAMESPACES) for key in keys}
 
 
 class CreateMultipartDepositClient(BaseCreateDepositClient):
diff --git a/swh/deposit/config.py b/swh/deposit/config.py
--- a/swh/deposit/config.py
+++ b/swh/deposit/config.py
@@ -29,7 +29,6 @@
 PRIVATE_LIST_DEPOSITS = "private-deposit-list"
 
 ARCHIVE_KEY = "archive"
-METADATA_KEY = "metadata"
 RAW_METADATA_KEY = "raw-metadata"
 
 ARCHIVE_TYPE = "archive"
diff --git a/swh/deposit/parsers.py b/swh/deposit/parsers.py
--- a/swh/deposit/parsers.py
+++ b/swh/deposit/parsers.py
@@ -9,13 +9,12 @@
 """
 
 import logging
-from xml.parsers.expat import ExpatError
+from xml.etree import ElementTree
 
 from django.conf import settings
 from rest_framework.parsers import BaseParser, FileUploadParser, MultiPartParser
 
 from swh.deposit.errors import ParserError
-from swh.deposit.utils import parse_xml as _parse_xml
 
 logger = logging.getLogger(__name__)
 
@@ -49,7 +48,8 @@
         """
         parser_context = parser_context or {}
         encoding = parser_context.get("encoding", settings.DEFAULT_CHARSET)
-        return _parse_xml(stream, encoding=encoding)
+        parser = ElementTree.XMLParser(encoding=encoding)
+        return ElementTree.parse(stream, parser=parser)
 
 
 class SWHAtomEntryParser(SWHXMLParser):
@@ -89,6 +89,6 @@
 
     """
     try:
-        return SWHXMLParser().parse(raw_content)
-    except ExpatError as e:
+        return ElementTree.fromstring(raw_content)
+    except ElementTree.ParseError as e:
         raise ParserError(str(e))
diff --git a/swh/deposit/tests/api/conftest.py b/swh/deposit/tests/api/conftest.py
--- a/swh/deposit/tests/api/conftest.py
+++ b/swh/deposit/tests/api/conftest.py
@@ -17,6 +17,7 @@
 )
 from swh.deposit.models import Deposit
 from swh.deposit.parsers import parse_xml
+from swh.deposit.utils import NAMESPACES
 
 
 @pytest.fixture
@@ -81,7 +82,7 @@
     )
 
     response_content = parse_xml(response.content)
-    deposit_id = int(response_content["swh:deposit_id"])
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
     deposit = Deposit.objects.get(pk=deposit_id)
     deposit.status = DEPOSIT_STATUS_DEPOSITED
     deposit.save()
diff --git a/swh/deposit/tests/api/test_collection_add_to_origin.py b/swh/deposit/tests/api/test_collection_add_to_origin.py
--- a/swh/deposit/tests/api/test_collection_add_to_origin.py
+++ b/swh/deposit/tests/api/test_collection_add_to_origin.py
@@ -3,8 +3,6 @@
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
-from io import BytesIO
-
 from django.urls import reverse_lazy as reverse
 from rest_framework import status
 
@@ -12,6 +10,7 @@
 from swh.deposit.models import Deposit
 from swh.deposit.parsers import parse_xml
 from swh.deposit.tests.common import post_atom
+from swh.deposit.utils import NAMESPACES
 
 from ..conftest import internal_create_deposit
 
@@ -40,8 +39,8 @@
     )
 
     assert response.status_code == status.HTTP_201_CREATED, response.content.decode()
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = parse_xml(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     assert deposit_id != deposit.id
 
diff --git a/swh/deposit/tests/api/test_collection_list.py b/swh/deposit/tests/api/test_collection_list.py
--- a/swh/deposit/tests/api/test_collection_list.py
+++ b/swh/deposit/tests/api/test_collection_list.py
@@ -3,8 +3,6 @@
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
-from io import BytesIO
-
 from django.urls import reverse_lazy as reverse
 from requests.utils import parse_header_links
 from rest_framework import status
@@ -12,6 +10,7 @@
 from swh.deposit.config import COL_IRI, DEPOSIT_STATUS_DEPOSITED, DEPOSIT_STATUS_PARTIAL
 from swh.deposit.models import DepositCollection
 from swh.deposit.parsers import parse_xml
+from swh.deposit.utils import NAMESPACES
 
 
 def test_deposit_collection_list_is_auth_protected(anonymous_client):
@@ -64,9 +63,9 @@
     response = authenticated_client.get(f"{url}?page_size=1")
     assert response.status_code == status.HTTP_200_OK
 
-    data = parse_xml(BytesIO(response.content))["atom:feed"]
+    data = parse_xml(response.content)
     assert (
-        data["swh:count"] == "2"
+        data.findtext("swh:count", namespaces=NAMESPACES) == "2"
     )  # total result of 2 deposits if consuming all results
     header_link = parse_header_links(response["Link"])
     assert len(header_link) == 1  # only 1 next link
@@ -75,17 +74,21 @@
     assert header_link[0]["rel"] == "next"
 
     # only one deposit in the response
-    deposit = data["atom:entry"]  # dict as only 1 value (a-la js)
-    assert isinstance(deposit, dict)
-    assert deposit["swh:id"] == deposit_id
-    assert deposit["swh:status"] == DEPOSIT_STATUS_PARTIAL
+    assert len(data.findall("atom:entry", namespaces=NAMESPACES)) == 1
+    assert data.findtext("atom:entry/swh:id", namespaces=NAMESPACES) == str(deposit_id)
+    assert (
+        data.findtext("atom:entry/swh:status", namespaces=NAMESPACES)
+        == DEPOSIT_STATUS_PARTIAL
+    )
 
     # then 2nd page
     response2 = authenticated_client.get(expected_next)
 
     assert response2.status_code == status.HTTP_200_OK
-    data2 = parse_xml(BytesIO(response2.content))["atom:feed"]
-    assert data2["swh:count"] == "2"  # still total of 2 deposits across all results
+    data2 = parse_xml(response2.content)
+    assert (
+        data2.findtext("swh:count", namespaces=NAMESPACES) == "2"
+    )  # still total of 2 deposits across all results
 
     expected_previous = f"{url}?page_size=1"
     header_link2 = parse_header_links(response2["Link"])
@@ -94,20 +97,26 @@
     assert header_link2[0]["rel"] == "previous"
 
     # only 1 deposit in the response
-    deposit2 = data2["atom:entry"]  # dict as only 1 value (a-la js)
-    assert isinstance(deposit2, dict)
-    assert deposit2["swh:id"] == deposit_id2
-    assert deposit2["swh:status"] == DEPOSIT_STATUS_DEPOSITED
+    assert len(data2.findall("atom:entry", namespaces=NAMESPACES)) == 1
+    assert data2.findtext("atom:entry/swh:id", namespaces=NAMESPACES) == str(
+        deposit_id2
+    )
+    assert (
+        data2.findtext("atom:entry/swh:status", namespaces=NAMESPACES)
+        == DEPOSIT_STATUS_DEPOSITED
+    )
 
     # Retrieve every deposit in one query (no page_size parameter)
     response3 = authenticated_client.get(url)
     assert response3.status_code == status.HTTP_200_OK
-    data3 = parse_xml(BytesIO(response3.content))["atom:feed"]
-    assert data3["swh:count"] == "2"  # total result of 2 deposits across all results
-    deposits3 = data3["atom:entry"]  # list here
+    data3 = parse_xml(response3.content)
+    assert (
+        data3.findtext("swh:count", namespaces=NAMESPACES) == "2"
+    )  # total result of 2 deposits across all results
+    deposits3 = data3.findall("atom:entry/swh:id", namespaces=NAMESPACES)  # list here
     assert isinstance(deposits3, list)
     assert len(deposits3) == 2
     header_link3 = parse_header_links(response3["Link"])
     assert header_link3 == []  # no pagination as all results received in one round
-    assert deposit in deposits3
-    assert deposit2 in deposits3
+    assert deposits3[0].text == str(deposit_id)
+    assert deposits3[1].text == str(deposit_id2)
diff --git a/swh/deposit/tests/api/test_collection_post_atom.py b/swh/deposit/tests/api/test_collection_post_atom.py
--- a/swh/deposit/tests/api/test_collection_post_atom.py
+++ b/swh/deposit/tests/api/test_collection_post_atom.py
@@ -5,10 +5,10 @@
 
 """Tests the handling of the Atom content when doing a POST Col-IRI."""
 
-from io import BytesIO
 import textwrap
 import uuid
 import warnings
+from xml.etree import ElementTree
 
 import attr
 from django.urls import reverse_lazy as reverse
@@ -22,9 +22,12 @@
     APIConfig,
 )
 from swh.deposit.models import Deposit, DepositCollection, DepositRequest
-from swh.deposit.parsers import parse_xml
 from swh.deposit.tests.common import post_atom
-from swh.deposit.utils import compute_metadata_context, extended_swhid_from_qualified
+from swh.deposit.utils import (
+    NAMESPACES,
+    compute_metadata_context,
+    extended_swhid_from_qualified,
+)
 from swh.model.hypothesis_strategies import (
     directories,
     present_contents,
@@ -121,14 +124,16 @@
     # then
     assert response.status_code == status.HTTP_201_CREATED, response.content.decode()
 
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = ElementTree.fromstring(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     deposit = Deposit.objects.get(pk=deposit_id)
     dr = DepositRequest.objects.get(deposit=deposit)
 
-    assert dr.metadata is not None
-    sw_version = dr.metadata.get("codemeta:softwareVersion")
+    assert dr.raw_metadata is not None
+    sw_version = ElementTree.fromstring(dr.raw_metadata).findtext(
+        "codemeta:softwareVersion", namespaces=NAMESPACES
+    )
     assert sw_version == "10.4"
 
 
@@ -145,7 +150,9 @@
         data=atom_content,
         HTTP_SLUG="external-id",
     )
-    assert response.status_code == status.HTTP_400_BAD_REQUEST
+    assert (
+        response.status_code == status.HTTP_400_BAD_REQUEST
+    ), response.content.decode()
     assert b"Empty body request is not supported" in response.content
 
 
@@ -259,8 +266,8 @@
     )
 
     assert response.status_code == status.HTTP_201_CREATED
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = ElementTree.fromstring(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     deposit = Deposit.objects.get(pk=deposit_id)
     assert deposit.collection == deposit_collection
@@ -288,8 +295,8 @@
     )
 
     assert response.status_code == status.HTTP_201_CREATED
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = ElementTree.fromstring(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     deposit = Deposit.objects.get(pk=deposit_id)
     assert deposit.collection == deposit_collection
@@ -318,8 +325,8 @@
     )
 
     assert response.status_code == status.HTTP_201_CREATED
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = ElementTree.fromstring(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     deposit = Deposit.objects.get(pk=deposit_id)
     assert deposit.collection == deposit_collection
@@ -443,8 +450,8 @@
     # then
     assert response.status_code == status.HTTP_201_CREATED, response.content.decode()
 
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = ElementTree.fromstring(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     deposit = Deposit.objects.get(pk=deposit_id)
     assert deposit.collection == deposit_collection
@@ -453,7 +460,6 @@
 
     # one associated request to a deposit
     deposit_request = DepositRequest.objects.get(deposit=deposit)
-    assert deposit_request.metadata is not None
     assert deposit_request.raw_metadata == atom_entry_data
     assert bool(deposit_request.archive) is False
 
@@ -482,9 +488,9 @@
     # then
     assert response.status_code == status.HTTP_201_CREATED
 
-    response_content = parse_xml(BytesIO(response.content))
+    response_content = ElementTree.fromstring(response.content)
 
-    deposit_id = response_content["swh:deposit_id"]
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     deposit = Deposit.objects.get(pk=deposit_id)
     assert deposit.collection == deposit_collection
@@ -493,7 +499,6 @@
 
     # one associated request to a deposit
     deposit_request = DepositRequest.objects.get(deposit=deposit)
-    assert deposit_request.metadata is not None
     assert deposit_request.raw_metadata == atom_entry_data
     assert bool(deposit_request.archive) is False
 
@@ -572,10 +577,10 @@
     )
 
     assert response.status_code == status.HTTP_201_CREATED, response.content.decode()
-    response_content = parse_xml(BytesIO(response.content))
+    response_content = ElementTree.fromstring(response.content)
 
     # Ensure the deposit is finalized
-    deposit_id = int(response_content["swh:deposit_id"])
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
     deposit = Deposit.objects.get(pk=deposit_id)
     assert deposit.swhid == str(swhid_target)
     assert deposit.swhid_context == str(swhid_reference)
@@ -650,9 +655,9 @@
     )
 
     assert response.status_code == status.HTTP_201_CREATED, response.content.decode()
-    response_content = parse_xml(BytesIO(response.content))
+    response_content = ElementTree.fromstring(response.content)
     # Ensure the deposit is finalized
-    deposit_id = int(response_content["swh:deposit_id"])
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
     deposit = Deposit.objects.get(pk=deposit_id)
     # we got not swhid as input so we cannot have those
     assert deposit.swhid is None
@@ -738,8 +743,10 @@
     assert (
         response.status_code == status.HTTP_400_BAD_REQUEST
     ), response.content.decode()
-    response_content = parse_xml(BytesIO(response.content))
-    assert "object does not exist" in response_content["sword:error"]["atom:summary"]
+    response_content = ElementTree.fromstring(response.content)
+    assert "object does not exist" in response_content.findtext(
+        "atom:summary", namespaces=NAMESPACES
+    )
 
 
 @pytest.mark.parametrize(
@@ -767,8 +774,10 @@
     assert (
         response.status_code == status.HTTP_400_BAD_REQUEST
     ), response.content.decode()
-    response_content = parse_xml(BytesIO(response.content))
-    assert "Invalid SWHID reference" in response_content["sword:error"]["atom:summary"]
+    response_content = ElementTree.fromstring(response.content)
+    assert "Invalid SWHID reference" in response_content.findtext(
+        "atom:summary", namespaces=NAMESPACES
+    )
 
 
 def test_deposit_metadata_unknown_origin(
@@ -788,5 +797,7 @@
     assert (
         response.status_code == status.HTTP_400_BAD_REQUEST
     ), response.content.decode()
-    response_content = parse_xml(BytesIO(response.content))
-    assert "known to the archive" in response_content["sword:error"]["atom:summary"]
+    response_content = ElementTree.fromstring(response.content)
+    assert "known to the archive" in response_content.findtext(
+        "atom:summary", namespaces=NAMESPACES
+    )
diff --git a/swh/deposit/tests/api/test_collection_post_binary.py b/swh/deposit/tests/api/test_collection_post_binary.py
--- a/swh/deposit/tests/api/test_collection_post_binary.py
+++ b/swh/deposit/tests/api/test_collection_post_binary.py
@@ -5,7 +5,6 @@
 
 """Tests the handling of the binary content when doing a POST Col-IRI."""
 
-from io import BytesIO
 import uuid
 
 from django.urls import reverse_lazy as reverse
@@ -20,6 +19,7 @@
     create_arborescence_archive,
     post_archive,
 )
+from swh.deposit.utils import NAMESPACES
 
 
 def test_post_deposit_binary_no_slug(
@@ -39,8 +39,8 @@
     )
 
     assert response.status_code == status.HTTP_201_CREATED
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = parse_xml(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     deposit = Deposit.objects.get(pk=deposit_id)
     assert deposit.collection == deposit_collection
@@ -96,9 +96,9 @@
     )
 
     # then
-    response_content = parse_xml(BytesIO(response.content))
+    response_content = parse_xml(response.content)
     assert response.status_code == status.HTTP_201_CREATED
-    deposit_id = response_content["swh:deposit_id"]
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     deposit = Deposit.objects.get(pk=deposit_id)
     assert deposit.status == DEPOSIT_STATUS_DEPOSITED
@@ -112,16 +112,34 @@
     assert deposit_request.metadata is None
     assert deposit_request.raw_metadata is None
 
-    response_content = parse_xml(BytesIO(response.content))
+    response_content = parse_xml(response.content)
 
-    assert response_content["swh:deposit_archive"] == sample_archive["name"]
-    assert int(response_content["swh:deposit_id"]) == deposit.id
-    assert response_content["swh:deposit_status"] == deposit.status
+    assert (
+        response_content.findtext("swh:deposit_archive", namespaces=NAMESPACES)
+        == sample_archive["name"]
+    )
+    assert (
+        int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
+        == deposit.id
+    )
+    assert (
+        response_content.findtext("swh:deposit_status", namespaces=NAMESPACES)
+        == deposit.status
+    )
 
     # deprecated tags
-    assert response_content["atom:deposit_archive"] == sample_archive["name"]
-    assert int(response_content["atom:deposit_id"]) == deposit.id
-    assert response_content["atom:deposit_status"] == deposit.status
+    assert (
+        response_content.findtext("atom:deposit_archive", namespaces=NAMESPACES)
+        == sample_archive["name"]
+    )
+    assert (
+        int(response_content.findtext("atom:deposit_id", namespaces=NAMESPACES))
+        == deposit.id
+    )
+    assert (
+        response_content.findtext("atom:deposit_status", namespaces=NAMESPACES)
+        == deposit.status
+    )
 
     from django.urls import reverse as reverse_strict
 
@@ -303,8 +321,8 @@
     # then
     assert response.status_code == status.HTTP_201_CREATED
 
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = parse_xml(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     deposit = Deposit.objects.get(pk=deposit_id)
 
@@ -324,8 +342,10 @@
 
     assert response.status_code == status.HTTP_201_CREATED
 
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id2 = response_content["swh:deposit_id"]
+    response_content = parse_xml(response.content)
+    deposit_id2 = int(
+        response_content.findtext("swh:deposit_id", namespaces=NAMESPACES)
+    )
 
     deposit2 = Deposit.objects.get(pk=deposit_id2)
 
diff --git a/swh/deposit/tests/api/test_collection_post_multipart.py b/swh/deposit/tests/api/test_collection_post_multipart.py
--- a/swh/deposit/tests/api/test_collection_post_multipart.py
+++ b/swh/deposit/tests/api/test_collection_post_multipart.py
@@ -17,6 +17,7 @@
 from swh.deposit.models import Deposit, DepositRequest
 from swh.deposit.parsers import parse_xml
 from swh.deposit.tests.common import check_archive, post_multipart
+from swh.deposit.utils import NAMESPACES
 
 
 def test_post_deposit_multipart(
@@ -43,8 +44,8 @@
     )
 
     assert response.status_code == status.HTTP_201_CREATED
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = parse_xml(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     deposit = Deposit.objects.get(pk=deposit_id)
     assert deposit.collection == deposit_collection
@@ -76,8 +77,8 @@
     )
 
     assert response.status_code == status.HTTP_201_CREATED
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = parse_xml(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     deposit = Deposit.objects.get(pk=deposit_id)
     assert deposit.collection == deposit_collection
@@ -109,8 +110,8 @@
     # then
     assert response.status_code == status.HTTP_201_CREATED
 
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = parse_xml(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     deposit = Deposit.objects.get(pk=deposit_id)
     assert deposit.status == DEPOSIT_STATUS_DEPOSITED
@@ -124,11 +125,12 @@
         assert deposit_request.deposit == deposit
         if deposit_request.type == "archive":
             check_archive(sample_archive["name"], deposit_request.archive.name)
-            assert deposit_request.metadata is None
             assert deposit_request.raw_metadata is None
         else:
             assert (
-                deposit_request.metadata["atom:id"]
+                parse_xml(deposit_request.raw_metadata).findtext(
+                    "atom:id", namespaces=NAMESPACES
+                )
                 == "urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a"
             )
             assert deposit_request.raw_metadata == data_atom_entry
@@ -158,8 +160,8 @@
     # then
     assert response.status_code == status.HTTP_201_CREATED
 
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = parse_xml(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     deposit = Deposit.objects.get(pk=deposit_id)
     assert deposit.status == DEPOSIT_STATUS_DEPOSITED
@@ -173,11 +175,12 @@
         assert deposit_request.deposit == deposit
         if deposit_request.type == "archive":
             check_archive(sample_archive["name"], deposit_request.archive.name)
-            assert deposit_request.metadata is None
             assert deposit_request.raw_metadata is None
         else:
             assert (
-                deposit_request.metadata["atom:id"]
+                parse_xml(deposit_request.raw_metadata).findtext(
+                    "atom:id", namespaces=NAMESPACES
+                )
                 == "urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a"
             )
             assert deposit_request.raw_metadata == data_atom_entry
@@ -208,8 +211,8 @@
     # then
     assert response.status_code == status.HTTP_201_CREATED
 
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = parse_xml(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     deposit = Deposit.objects.get(pk=deposit_id)
     assert deposit.status == "partial"
@@ -226,7 +229,9 @@
             check_archive(sample_archive["name"], deposit_request.archive.name)
         else:
             assert (
-                deposit_request.metadata["atom:id"]
+                parse_xml(deposit_request.raw_metadata).findtext(
+                    "atom:id", namespaces=NAMESPACES
+                )
                 == "urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a"
             )
             assert deposit_request.raw_metadata == data_atom_entry
@@ -256,7 +261,9 @@
             check_archive(sample_archive["name"], deposit_request.archive.name)
         else:
             assert (
-                deposit_request.metadata["atom:id"]
+                parse_xml(deposit_request.raw_metadata).findtext(
+                    "atom:id", namespaces=NAMESPACES
+                )
                 == "urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a"
             )
             assert (
diff --git a/swh/deposit/tests/api/test_collection_reuse_slug.py b/swh/deposit/tests/api/test_collection_reuse_slug.py
--- a/swh/deposit/tests/api/test_collection_reuse_slug.py
+++ b/swh/deposit/tests/api/test_collection_reuse_slug.py
@@ -3,11 +3,8 @@
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
-from io import BytesIO
-
 from django.urls import reverse_lazy as reverse
 from rest_framework import status
-import xmltodict
 
 from swh.deposit.config import (
     COL_IRI,
@@ -19,6 +16,7 @@
 from swh.deposit.models import Deposit
 from swh.deposit.parsers import parse_xml
 from swh.deposit.tests.common import post_atom
+from swh.deposit.utils import NAMESPACES
 
 from ..conftest import internal_create_deposit
 
@@ -36,8 +34,9 @@
     )
 
     assert response.status_code == status.HTTP_400_BAD_REQUEST
+    print(response.content)
     assert (
-        xmltodict.parse(response.content)["sword:error"]["summary"]
+        parse_xml(response.content).findtext("atom:summary", namespaces=NAMESPACES)
         == f"You can only act on deposit with status '{DEPOSIT_STATUS_PARTIAL}'"
     )
 
@@ -65,8 +64,8 @@
     )
 
     assert response.status_code == status.HTTP_201_CREATED, response.content.decode()
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = parse_xml(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     assert deposit_id != deposit.id  # new deposit
 
@@ -97,8 +96,8 @@
     )
 
     assert response.status_code == status.HTTP_201_CREATED
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = parse_xml(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     assert deposit_id != deposit.id
 
@@ -134,8 +133,8 @@
     )
 
     assert response.status_code == status.HTTP_201_CREATED
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = parse_xml(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     assert deposit_id != deposit.id
 
@@ -174,8 +173,8 @@
     )
 
     assert response.status_code == status.HTTP_201_CREATED
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = parse_xml(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     assert deposit_id != deposit.id
 
@@ -220,8 +219,8 @@
     )
 
     assert response.status_code == status.HTTP_201_CREATED
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = parse_xml(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     assert other_deposit.id != deposit_id
 
@@ -269,8 +268,8 @@
     )
 
     assert response.status_code == status.HTTP_201_CREATED
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = parse_xml(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     assert deposit_id != deposit.id
     assert other_deposit.id != deposit.id
diff --git a/swh/deposit/tests/api/test_delete.py b/swh/deposit/tests/api/test_delete.py
--- a/swh/deposit/tests/api/test_delete.py
+++ b/swh/deposit/tests/api/test_delete.py
@@ -11,11 +11,11 @@
 import xmltodict
 
 from swh.deposit.config import (
-    ARCHIVE_KEY,
+    ARCHIVE_TYPE,
     DEPOSIT_STATUS_DEPOSITED,
     EDIT_IRI,
     EM_IRI,
-    METADATA_KEY,
+    METADATA_TYPE,
 )
 from swh.deposit.models import Deposit, DepositRequest
 
@@ -39,7 +39,7 @@
 
     # deposit request type: 'archive', 1 'metadata'
     deposit_request_types = count_deposit_request_types(deposit_requests)
-    assert deposit_request_types == {ARCHIVE_KEY: 1, METADATA_KEY: 1}
+    assert deposit_request_types == {ARCHIVE_TYPE: 1, METADATA_TYPE: 1}
 
     # when
     update_uri = reverse(EM_IRI, args=[deposit_collection.name, deposit_id])
@@ -52,7 +52,7 @@
     deposit_requests2 = DepositRequest.objects.filter(deposit=deposit)
 
     deposit_request_types = count_deposit_request_types(deposit_requests2)
-    assert deposit_request_types == {METADATA_KEY: 1}
+    assert deposit_request_types == {METADATA_TYPE: 1}
 
 
 def test_delete_archive_on_undefined_deposit_fails(
diff --git a/swh/deposit/tests/api/test_deposit_private_check.py b/swh/deposit/tests/api/test_deposit_private_check.py
--- a/swh/deposit/tests/api/test_deposit_private_check.py
+++ b/swh/deposit/tests/api/test_deposit_private_check.py
@@ -26,6 +26,7 @@
     create_arborescence_archive,
     create_archive_with_archive,
 )
+from swh.deposit.utils import NAMESPACES
 
 PRIVATE_CHECK_DEPOSIT_NC = PRIVATE_CHECK_DEPOSIT + "-nc"
 
@@ -204,9 +205,11 @@
     # then
     assert response.status_code == status.HTTP_201_CREATED
     response_content = parse_xml(response.content)
-    deposit_status = response_content["swh:deposit_status"]
+    deposit_status = response_content.findtext(
+        "swh:deposit_status", namespaces=NAMESPACES
+    )
     assert deposit_status == DEPOSIT_STATUS_DEPOSITED
-    deposit_id = int(response_content["swh:deposit_id"])
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     deposit = Deposit.objects.get(pk=deposit_id)
     assert DEPOSIT_STATUS_DEPOSITED == deposit.status
diff --git a/swh/deposit/tests/api/test_deposit_schedule.py b/swh/deposit/tests/api/test_deposit_schedule.py
--- a/swh/deposit/tests/api/test_deposit_schedule.py
+++ b/swh/deposit/tests/api/test_deposit_schedule.py
@@ -5,7 +5,6 @@
 
 import copy
 import datetime
-from io import BytesIO
 
 from django.urls import reverse_lazy as reverse
 import pytest
@@ -18,6 +17,7 @@
     SE_IRI,
 )
 from swh.deposit.parsers import parse_xml
+from swh.deposit.utils import NAMESPACES
 
 
 @pytest.fixture()
@@ -81,10 +81,12 @@
 
     assert response.status_code == status.HTTP_201_CREATED
 
-    response_content = parse_xml(BytesIO(response.content))
-    actual_state = response_content["swh:deposit_status"]
+    response_content = parse_xml(response.content)
+    actual_state = response_content.findtext(
+        "swh:deposit_status", namespaces=NAMESPACES
+    )
     assert actual_state == DEPOSIT_STATUS_DEPOSITED
-    deposit_id = int(response_content["swh:deposit_id"])
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     assert_task_for_deposit(
         swh_scheduler, deposit_id, timestamp_before_call, timestamp_after_call
@@ -123,10 +125,14 @@
 
     assert response.status_code == status.HTTP_200_OK
 
-    response_content = parse_xml(BytesIO(response.content))
-    actual_state = response_content["swh:deposit_status"]
+    response_content = parse_xml(response.content)
+    actual_state = response_content.findtext(
+        "swh:deposit_status", namespaces=NAMESPACES
+    )
     assert actual_state == DEPOSIT_STATUS_DEPOSITED
-    assert deposit.id == int(response_content["swh:deposit_id"])
+    assert deposit.id == int(
+        response_content.findtext("swh:deposit_id", namespaces=NAMESPACES)
+    )
 
     assert_task_for_deposit(
         swh_scheduler, deposit.id, timestamp_before_call, timestamp_after_call
diff --git a/swh/deposit/tests/api/test_deposit_state.py b/swh/deposit/tests/api/test_deposit_state.py
--- a/swh/deposit/tests/api/test_deposit_state.py
+++ b/swh/deposit/tests/api/test_deposit_state.py
@@ -4,7 +4,7 @@
 # See top-level LICENSE file for more information
 
 
-from io import BytesIO
+from xml.etree import ElementTree
 
 from django.urls import reverse_lazy as reverse
 from rest_framework import status
@@ -15,7 +15,7 @@
     STATE_IRI,
 )
 from swh.deposit.models import DEPOSIT_STATUS_DETAIL, DEPOSIT_STATUS_LOAD_SUCCESS
-from swh.deposit.parsers import parse_xml
+from swh.deposit.utils import NAMESPACES
 
 
 def test_post_deposit_with_status_check(authenticated_client, deposited_deposit):
@@ -29,16 +29,25 @@
     status_response = authenticated_client.get(status_url)
 
     assert status_response.status_code == status.HTTP_200_OK
-    r = parse_xml(BytesIO(status_response.content))
+    r = ElementTree.fromstring(status_response.content)
 
-    assert int(r["swh:deposit_id"]) == deposit.id
-    assert r["swh:deposit_status"] == DEPOSIT_STATUS_DEPOSITED
+    assert int(r.findtext("swh:deposit_id", namespaces=NAMESPACES)) == deposit.id
     assert (
-        r["swh:deposit_status_detail"]
+        r.findtext("swh:deposit_status", namespaces=NAMESPACES)
+        == DEPOSIT_STATUS_DEPOSITED
+    )
+    assert (
+        r.findtext("swh:deposit_status_detail", namespaces=NAMESPACES)
         == DEPOSIT_STATUS_DETAIL[DEPOSIT_STATUS_DEPOSITED]
     )
-    assert r["swh:deposit_external_id"] == deposit.external_id
-    assert r["swh:deposit_origin_url"] == deposit.origin_url
+    assert (
+        r.findtext("swh:deposit_external_id", namespaces=NAMESPACES)
+        == deposit.external_id
+    )
+    assert (
+        r.findtext("swh:deposit_origin_url", namespaces=NAMESPACES)
+        == deposit.origin_url
+    )
 
 
 def test_status_unknown_deposit(authenticated_client, deposit_collection):
@@ -74,12 +83,18 @@
 
     # then
     assert status_response.status_code == status.HTTP_200_OK
-    r = parse_xml(BytesIO(status_response.content))
-    assert int(r["swh:deposit_id"]) == deposit.id
-    assert r["swh:deposit_status"] == DEPOSIT_STATUS_REJECTED
-    assert r["swh:deposit_status_detail"] == "Deposit failed the checks"
+    r = ElementTree.fromstring(status_response.content)
+    assert int(r.findtext("swh:deposit_id", namespaces=NAMESPACES)) == deposit.id
+    assert (
+        r.findtext("swh:deposit_status", namespaces=NAMESPACES)
+        == DEPOSIT_STATUS_REJECTED
+    )
+    assert (
+        r.findtext("swh:deposit_status_detail", namespaces=NAMESPACES)
+        == "Deposit failed the checks"
+    )
     if deposit.swhid:
-        assert r["swh:deposit_swhid"] == deposit.swhid
+        assert r.findtext("swh:deposit_swhid", namespaces=NAMESPACES) == deposit.swhid
 
 
 def test_status_with_http_accept_header_should_not_break(
@@ -113,15 +128,24 @@
 
     # then
     assert status_response.status_code == status.HTTP_200_OK
-    r = parse_xml(BytesIO(status_response.content))
-    assert int(r["swh:deposit_id"]) == deposit.id
-    assert r["swh:deposit_status"] == DEPOSIT_STATUS_LOAD_SUCCESS
+    r = ElementTree.fromstring(status_response.content)
+    assert int(r.findtext("swh:deposit_id", namespaces=NAMESPACES)) == deposit.id
+    assert (
+        r.findtext("swh:deposit_status", namespaces=NAMESPACES)
+        == DEPOSIT_STATUS_LOAD_SUCCESS
+    )
     assert (
-        r["swh:deposit_status_detail"]
+        r.findtext("swh:deposit_status_detail", namespaces=NAMESPACES)
         == DEPOSIT_STATUS_DETAIL[DEPOSIT_STATUS_LOAD_SUCCESS]
     )
     assert deposit.swhid is not None
-    assert r["swh:deposit_swh_id"] == deposit.swhid
+    assert r.findtext("swh:deposit_swh_id", namespaces=NAMESPACES) == deposit.swhid
     assert deposit.swhid_context is not None
-    assert r["swh:deposit_swh_id_context"] == deposit.swhid_context
-    assert r["swh:deposit_origin_url"] == deposit.origin_url
+    assert (
+        r.findtext("swh:deposit_swh_id_context", namespaces=NAMESPACES)
+        == deposit.swhid_context
+    )
+    assert (
+        r.findtext("swh:deposit_origin_url", namespaces=NAMESPACES)
+        == deposit.origin_url
+    )
diff --git a/swh/deposit/tests/api/test_deposit_update_atom.py b/swh/deposit/tests/api/test_deposit_update_atom.py
--- a/swh/deposit/tests/api/test_deposit_update_atom.py
+++ b/swh/deposit/tests/api/test_deposit_update_atom.py
@@ -3,8 +3,6 @@
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
-from io import BytesIO
-
 from django.urls import reverse_lazy as reverse
 import pytest
 from rest_framework import status
@@ -21,6 +19,7 @@
 from swh.deposit.models import Deposit, DepositCollection, DepositRequest
 from swh.deposit.parsers import parse_xml
 from swh.deposit.tests.common import post_atom, put_atom
+from swh.deposit.utils import NAMESPACES
 from swh.model.hashutil import hash_to_bytes
 from swh.model.model import (
     MetadataAuthority,
@@ -55,8 +54,8 @@
     # then
     assert response.status_code == status.HTTP_201_CREATED
 
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = int(response_content["swh:deposit_id"])
+    response_content = parse_xml(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     deposit = Deposit.objects.get(pk=deposit_id)
     assert deposit.collection == deposit_collection
@@ -69,12 +68,9 @@
 
     atom_entry_data = atom_dataset["entry-only-create-origin"] % (origin_url)
 
-    for link in response_content["atom:link"]:
-        if link["@rel"] == "http://purl.org/net/sword/terms/add":
-            se_iri = link["@href"]
-            break
-    else:
-        assert False, f"missing SE-IRI from {response_content['link']}"
+    se_iri = response_content.find(
+        "atom:link[@rel='http://purl.org/net/sword/terms/add']", namespaces=NAMESPACES
+    ).attrib["href"]
 
     # when updating the first deposit post
     response = post_atom(
@@ -84,8 +80,8 @@
     # then
     assert response.status_code == status.HTTP_201_CREATED, response.content.decode()
 
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = int(response_content["swh:deposit_id"])
+    response_content = parse_xml(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
 
     deposit = Deposit.objects.get(pk=deposit_id)
     assert deposit.collection == deposit_collection
@@ -100,14 +96,12 @@
 
     atom_entry_data1 = atom_dataset["entry-data1"]
     expected_meta = [
-        {"metadata": parse_xml(atom_entry_data1), "raw_metadata": atom_entry_data1},
-        {"metadata": parse_xml(atom_entry_data), "raw_metadata": atom_entry_data},
+        atom_entry_data1,
+        atom_entry_data,
     ]
 
     for i, deposit_request in enumerate(deposit_requests):
-        actual_metadata = deposit_request.metadata
-        assert actual_metadata == expected_meta[i]["metadata"]
-        assert deposit_request.raw_metadata == expected_meta[i]["raw_metadata"]
+        assert deposit_request.raw_metadata == expected_meta[i]
         assert bool(deposit_request.archive) is False
 
 
@@ -216,8 +210,8 @@
     response = post_atom(authenticated_client, url, data=atom_dataset["entry-data1"],)
     assert response.status_code == status.HTTP_404_NOT_FOUND
     response_content = parse_xml(response.content)
-    assert (
-        "Deposit 1000 does not exist" in response_content["sword:error"]["atom:summary"]
+    assert "Deposit 1000 does not exist" in response_content.findtext(
+        "atom:summary", namespaces=NAMESPACES
     )
 
 
@@ -238,7 +232,9 @@
     response = post_atom(authenticated_client, url, data=atom_dataset["entry-data1"],)
     assert response.status_code == status.HTTP_404_NOT_FOUND
     response_content = parse_xml(response.content)
-    assert "Unknown collection name" in response_content["sword:error"]["atom:summary"]
+    assert "Unknown collection name" in response_content.findtext(
+        "atom:summary", namespaces=NAMESPACES
+    )
 
 
 def test_replace_metadata_to_unknown_deposit(
@@ -257,8 +253,8 @@
     assert response.status_code == status.HTTP_404_NOT_FOUND
     response_content = parse_xml(response.content)
     assert (
-        "Deposit %s does not exist" % unknown_deposit_id
-        == response_content["sword:error"]["atom:summary"]
+        response_content.findtext("atom:summary", namespaces=NAMESPACES)
+        == "Deposit %s does not exist" % unknown_deposit_id
     )
 
 
@@ -542,14 +538,11 @@
     )
 
     assert response.status_code == status.HTTP_201_CREATED
-    response_content = parse_xml(BytesIO(response.content))
+    response_content = parse_xml(response.content)
 
-    for link in response_content["atom:link"]:
-        if link["@rel"] == "edit":
-            edit_iri = link["@href"]
-            break
-    else:
-        assert False, response_content
+    edit_iri = response_content.find(
+        "atom:link[@rel='edit']", namespaces=NAMESPACES
+    ).attrib["href"]
 
     # when
     response = put_atom(
@@ -581,14 +574,11 @@
     )
 
     assert response.status_code == status.HTTP_201_CREATED
-    response_content = parse_xml(BytesIO(response.content))
-
-    for link in response_content["atom:link"]:
-        if link["@rel"] == "edit":
-            edit_iri = link["@href"]
-            break
-    else:
-        assert False, response_content
+    response_content = parse_xml(response.content)
+
+    edit_iri = response_content.find(
+        "atom:link[@rel='edit']", namespaces=NAMESPACES
+    ).attrib["href"]
 
     # when
     response = put_atom(
diff --git a/swh/deposit/tests/api/test_deposit_update_binary.py b/swh/deposit/tests/api/test_deposit_update_binary.py
--- a/swh/deposit/tests/api/test_deposit_update_binary.py
+++ b/swh/deposit/tests/api/test_deposit_update_binary.py
@@ -23,6 +23,7 @@
     put_archive,
     put_atom,
 )
+from swh.deposit.utils import NAMESPACES
 
 
 def test_post_deposit_binary_and_post_to_add_another_archive(
@@ -48,8 +49,8 @@
     # then
     assert response.status_code == status.HTTP_201_CREATED
 
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = parse_xml(response.content)
+    deposit_id = response_content.findtext("swh:deposit_id", namespaces=NAMESPACES)
 
     deposit = Deposit.objects.get(pk=deposit_id)
     assert deposit.status == "partial"
@@ -76,7 +77,7 @@
     )
 
     assert response.status_code == status.HTTP_201_CREATED
-    response_content = parse_xml(BytesIO(response.content))
+    response_content = parse_xml(response.content)
 
     deposit = Deposit.objects.get(pk=deposit_id)
     assert deposit.status == DEPOSIT_STATUS_DEPOSITED
@@ -182,8 +183,8 @@
     assert response.status_code == status.HTTP_404_NOT_FOUND
     response_content = parse_xml(response.content)
     assert (
-        "Deposit %s does not exist" % unknown_deposit_id
-        == response_content["sword:error"]["atom:summary"]
+        response_content.findtext("atom:summary", namespaces=NAMESPACES)
+        == "Deposit %s does not exist" % unknown_deposit_id
     )
 
 
@@ -206,8 +207,8 @@
     assert response.status_code == status.HTTP_404_NOT_FOUND
     response_content = parse_xml(response.content)
     assert (
-        "Deposit %s does not exist" % unknown_deposit_id
-        == response_content["sword:error"]["atom:summary"]
+        response_content.findtext("atom:summary", namespaces=NAMESPACES)
+        == "Deposit %s does not exist" % unknown_deposit_id
     )
 
 
@@ -288,8 +289,8 @@
     # then
     assert response.status_code == status.HTTP_201_CREATED
 
-    response_content = parse_xml(BytesIO(response.content))
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = parse_xml(response.content)
+    deposit_id = response_content.findtext("swh:deposit_id", namespaces=NAMESPACES)
 
     deposit = Deposit.objects.get(pk=deposit_id)
     assert deposit.status == DEPOSIT_STATUS_DEPOSITED
diff --git a/swh/deposit/tests/api/test_get_file.py b/swh/deposit/tests/api/test_get_file.py
--- a/swh/deposit/tests/api/test_get_file.py
+++ b/swh/deposit/tests/api/test_get_file.py
@@ -11,6 +11,7 @@
 from swh.deposit.config import CONT_FILE_IRI
 from swh.deposit.models import DEPOSIT_STATUS_DETAIL
 from swh.deposit.parsers import parse_xml
+from swh.deposit.utils import NAMESPACES
 
 
 def test_api_deposit_content_nominal(
@@ -21,18 +22,21 @@
     """
 
     for deposit in [complete_deposit, partial_deposit_only_metadata]:
-        expected_deposit = {
-            "swh:deposit_id": str(deposit.id),
-            "swh:deposit_status": deposit.status,
-            "swh:deposit_status_detail": DEPOSIT_STATUS_DETAIL[deposit.status],
-        }
-
         url = reverse(CONT_FILE_IRI, args=[deposit.collection.name, deposit.id])
         response = authenticated_client.get(url)
         assert response.status_code == status.HTTP_200_OK
-        actual_deposit = dict(parse_xml(response.content))
-        del actual_deposit["swh:deposit_date"]
-        assert set(actual_deposit.items()) >= set(expected_deposit.items())
+        actual_deposit = parse_xml(response.content)
+        assert actual_deposit.findtext("swh:deposit_id", namespaces=NAMESPACES) == str(
+            deposit.id
+        )
+        assert (
+            actual_deposit.findtext("swh:deposit_status", namespaces=NAMESPACES)
+            == deposit.status
+        )
+        assert (
+            actual_deposit.findtext("swh:deposit_status_detail", namespaces=NAMESPACES)
+            == DEPOSIT_STATUS_DETAIL[deposit.status]
+        )
 
 
 def test_api_deposit_content_unknown(
diff --git a/swh/deposit/tests/api/test_parsers.py b/swh/deposit/tests/api/test_parsers.py
--- a/swh/deposit/tests/api/test_parsers.py
+++ b/swh/deposit/tests/api/test_parsers.py
@@ -1,12 +1,12 @@
-# Copyright (C) 2018-2020  The Software Heritage developers
+# Copyright (C) 2018-2022  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
-from collections import OrderedDict
 import io
 
 from swh.deposit.parsers import SWHXMLParser
+from swh.deposit.utils import NAMESPACES
 
 
 def test_parsing_without_duplicates():
@@ -30,30 +30,23 @@
     )
 
     actual_result = SWHXMLParser().parse(xml_no_duplicate)
-    expected_dict = OrderedDict(
-        [
-            ("atom:title", "Awesome Compiler"),
-            (
-                "codemeta:license",
-                OrderedDict(
-                    [
-                        ("codemeta:name", "GPL3.0"),
-                        ("codemeta:url", "https://opensource.org/licenses/GPL-3.0"),
-                    ]
-                ),
-            ),
-            ("codemeta:runtimePlatform", "Python3"),
-            (
-                "codemeta:author",
-                OrderedDict(
-                    [("codemeta:name", "author1"), ("codemeta:affiliation", "Inria")]
-                ),
-            ),
-            ("codemeta:programmingLanguage", "ocaml"),
-            ("codemeta:issueTracker", "http://issuetracker.com"),
-        ]
+
+    assert (
+        actual_result.findtext(
+            "codemeta:license/codemeta:name",
+            namespaces={"codemeta": "https://doi.org/10.5063/SCHEMA/CODEMETA-2.0"},
+        )
+        == "GPL3.0"
+    )
+    assert (
+        actual_result.findtext("codemeta:license/codemeta:name", namespaces=NAMESPACES)
+        == "GPL3.0"
+    )
+    authors = actual_result.findall(
+        "codemeta:author/codemeta:name", namespaces=NAMESPACES
     )
-    assert expected_dict == actual_result
+    assert len(authors) == 1
+    assert authors[0].text == "author1"
 
 
 def test_parsing_with_duplicates():
@@ -88,42 +81,20 @@
 
     actual_result = SWHXMLParser().parse(xml_with_duplicates)
 
-    expected_dict = OrderedDict(
-        [
-            ("atom:title", "Another Compiler"),
-            ("codemeta:runtimePlatform", ["GNU/Linux", "Un*x"]),
-            (
-                "codemeta:license",
-                [
-                    OrderedDict(
-                        [
-                            ("codemeta:name", "GPL3.0"),
-                            ("codemeta:url", "https://opensource.org/licenses/GPL-3.0"),
-                        ]
-                    ),
-                    OrderedDict(
-                        [("codemeta:name", "spdx"), ("codemeta:url", "http://spdx.org")]
-                    ),
-                ],
-            ),
-            (
-                "codemeta:author",
-                [
-                    OrderedDict(
-                        [
-                            ("codemeta:name", "author1"),
-                            ("codemeta:affiliation", "Inria"),
-                        ]
-                    ),
-                    OrderedDict(
-                        [
-                            ("codemeta:name", "author2"),
-                            ("codemeta:affiliation", "Inria"),
-                        ]
-                    ),
-                ],
-            ),
-            ("codemeta:programmingLanguage", ["ocaml", "haskell", "python3"]),
-        ]
+    assert (
+        actual_result.findtext(
+            "codemeta:license/codemeta:name",
+            namespaces={"codemeta": "https://doi.org/10.5063/SCHEMA/CODEMETA-2.0"},
+        )
+        == "GPL3.0"
+    )
+    assert (
+        actual_result.findtext("codemeta:license/codemeta:name", namespaces=NAMESPACES)
+        == "GPL3.0"
+    )
+    authors = actual_result.findall(
+        "codemeta:author/codemeta:name", namespaces=NAMESPACES
     )
-    assert expected_dict == actual_result
+    assert len(authors) == 2
+    assert authors[0].text == "author1"
+    assert authors[1].text == "author2"
diff --git a/swh/deposit/tests/cli/test_client.py b/swh/deposit/tests/cli/test_client.py
--- a/swh/deposit/tests/cli/test_client.py
+++ b/swh/deposit/tests/cli/test_client.py
@@ -4,7 +4,6 @@
 # See top-level LICENSE file for more information
 
 import ast
-from collections import OrderedDict
 import contextlib
 import json
 import logging
@@ -29,6 +28,7 @@
     ServiceDocumentDepositClient,
 )
 from swh.deposit.parsers import parse_xml
+from swh.deposit.utils import NAMESPACES
 from swh.model.exceptions import ValidationError
 
 from ..conftest import TEST_USER
@@ -183,22 +183,39 @@
         metadata_provenance_url="meta-prov-url",
     )
 
-    actual_metadata = dict(parse_xml(actual_metadata_xml))
-    assert actual_metadata["atom:author"] == "deposit-client"
-    assert actual_metadata["atom:title"] == "project-name"
-    assert actual_metadata["atom:updated"] is not None
-    assert actual_metadata["codemeta:name"] == "project-name"
-    assert actual_metadata["codemeta:identifier"] == "external-id"
-    assert actual_metadata["codemeta:author"] == [
-        OrderedDict([("codemeta:name", "some")]),
-        OrderedDict([("codemeta:name", "authors")]),
-    ]
+    actual_metadata = parse_xml(actual_metadata_xml)
     assert (
-        actual_metadata["swh:deposit"]["swh:create_origin"]["swh:origin"]["@url"]
+        actual_metadata.findtext("atom:author", namespaces=NAMESPACES)
+        == "deposit-client"
+    )
+    assert (
+        actual_metadata.findtext("atom:title", namespaces=NAMESPACES) == "project-name"
+    )
+    assert actual_metadata.findtext("atom:updated", namespaces=NAMESPACES) is not None
+    assert (
+        actual_metadata.findtext("codemeta:name", namespaces=NAMESPACES)
+        == "project-name"
+    )
+    assert (
+        actual_metadata.findtext("codemeta:identifier", namespaces=NAMESPACES)
+        == "external-id"
+    )
+    authors = actual_metadata.findall(
+        "codemeta:author/codemeta:name", namespaces=NAMESPACES
+    )
+    assert len(authors) == 2
+    assert authors[0].text == "some"
+    assert authors[1].text == "authors"
+    assert (
+        actual_metadata.find(
+            "swh:deposit/swh:create_origin/swh:origin", namespaces=NAMESPACES
+        ).attrib["url"]
         == "origin-url"
     )
     assert (
-        actual_metadata["swh:deposit"]["swh:metadata-provenance"]["schema:url"]
+        actual_metadata.findtext(
+            "swh:deposit/swh:metadata-provenance/schema:url", namespaces=NAMESPACES
+        )
         == "meta-prov-url"
     )
 
@@ -216,17 +233,27 @@
         "deposit-client", "project-name", authors=["some", "authors"],
     )
 
-    actual_metadata = dict(parse_xml(actual_metadata_xml))
-    assert actual_metadata["atom:author"] == "deposit-client"
-    assert actual_metadata["atom:title"] == "project-name"
-    assert actual_metadata["atom:updated"] is not None
-    assert actual_metadata["codemeta:name"] == "project-name"
-    assert actual_metadata["codemeta:author"] == [
-        OrderedDict([("codemeta:name", "some")]),
-        OrderedDict([("codemeta:name", "authors")]),
-    ]
-    assert actual_metadata.get("codemeta:identifier") is None
-    assert actual_metadata.get("swh:deposit") is None
+    actual_metadata = parse_xml(actual_metadata_xml)
+    assert (
+        actual_metadata.findtext("atom:author", namespaces=NAMESPACES)
+        == "deposit-client"
+    )
+    assert (
+        actual_metadata.findtext("atom:title", namespaces=NAMESPACES) == "project-name"
+    )
+    assert actual_metadata.findtext("atom:updated", namespaces=NAMESPACES) is not None
+    assert (
+        actual_metadata.findtext("codemeta:name", namespaces=NAMESPACES)
+        == "project-name"
+    )
+    authors = actual_metadata.findall(
+        "codemeta:author/codemeta:name", namespaces=NAMESPACES
+    )
+    assert len(authors) == 2
+    assert authors[0].text == "some"
+    assert authors[1].text == "authors"
+    assert actual_metadata.find("codemeta:identifier", namespaces=NAMESPACES) is None
+    assert actual_metadata.find("swh:deposit", namespaces=NAMESPACES) is None
 
     checks_ok, detail = check_metadata(ElementTree.fromstring(actual_metadata_xml))
 
@@ -273,15 +300,31 @@
     }
 
     with open(metadata_path) as fd:
-        actual_metadata = dict(parse_xml(fd.read()))
-        assert actual_metadata["atom:author"] == TEST_USER["username"]
-        assert actual_metadata["codemeta:name"] == "test-project"
-        assert actual_metadata["atom:title"] == "test-project"
-        assert actual_metadata["atom:updated"] is not None
-        assert actual_metadata["codemeta:identifier"] == slug
-        assert actual_metadata["codemeta:author"] == OrderedDict(
-            [("codemeta:name", "Jane Doe")]
+        actual_metadata = parse_xml(fd.read())
+        assert (
+            actual_metadata.findtext("atom:author", namespaces=NAMESPACES)
+            == TEST_USER["username"]
         )
+        assert (
+            actual_metadata.findtext("codemeta:name", namespaces=NAMESPACES)
+            == "test-project"
+        )
+        assert (
+            actual_metadata.findtext("atom:title", namespaces=NAMESPACES)
+            == "test-project"
+        )
+        assert (
+            actual_metadata.findtext("atom:updated", namespaces=NAMESPACES) is not None
+        )
+        assert (
+            actual_metadata.findtext("codemeta:identifier", namespaces=NAMESPACES)
+            == slug
+        )
+        authors = actual_metadata.findall(
+            "codemeta:author/codemeta:name", namespaces=NAMESPACES
+        )
+        assert len(authors) == 1
+        assert authors[0].text == "Jane Doe"
 
     count_warnings = 0
     for (_, log_level, _) in caplog.record_tuples:
@@ -329,22 +372,39 @@
     }
 
     with open(metadata_path) as fd:
-        actual_metadata = dict(parse_xml(fd.read()))
-        assert actual_metadata["atom:author"] == TEST_USER["username"]
-        assert actual_metadata["codemeta:name"] == "test-project"
-        assert actual_metadata["atom:title"] == "test-project"
-        assert actual_metadata["atom:updated"] is not None
+        actual_metadata = parse_xml(fd.read())
+        assert (
+            actual_metadata.findtext("atom:author", namespaces=NAMESPACES)
+            == TEST_USER["username"]
+        )
+        assert (
+            actual_metadata.findtext("codemeta:name", namespaces=NAMESPACES)
+            == "test-project"
+        )
+        assert (
+            actual_metadata.findtext("atom:title", namespaces=NAMESPACES)
+            == "test-project"
+        )
+        assert (
+            actual_metadata.findtext("atom:updated", namespaces=NAMESPACES) is not None
+        )
         assert (
-            actual_metadata["swh:deposit"]["swh:create_origin"]["swh:origin"]["@url"]
+            actual_metadata.find(
+                "swh:deposit/swh:create_origin/swh:origin", namespaces=NAMESPACES
+            ).attrib["url"]
             == origin
         )
         assert (
-            actual_metadata["swh:deposit"]["swh:metadata-provenance"]["schema:url"]
+            actual_metadata.findtext(
+                "swh:deposit/swh:metadata-provenance/schema:url", namespaces=NAMESPACES
+            )
             == "meta-prov-url"
         )
-        assert actual_metadata["codemeta:author"] == OrderedDict(
-            [("codemeta:name", "Jane Doe")]
+        authors = actual_metadata.findall(
+            "codemeta:author/codemeta:name", namespaces=NAMESPACES
         )
+        assert len(authors) == 1
+        assert authors[0].text == "Jane Doe"
 
     count_warnings = 0
     for (_, log_level, _) in caplog.record_tuples:
@@ -569,7 +629,7 @@
 
     with open(metadata_path) as fd:
         metadata_xml = fd.read()
-        actual_metadata = dict(parse_xml(metadata_xml))
+        actual_metadata = parse_xml(metadata_xml)
         assert "codemeta:identifier" not in actual_metadata
 
 
diff --git a/swh/deposit/tests/conftest.py b/swh/deposit/tests/conftest.py
--- a/swh/deposit/tests/conftest.py
+++ b/swh/deposit/tests/conftest.py
@@ -9,6 +9,7 @@
 import os
 import re
 from typing import TYPE_CHECKING, Dict, Mapping
+from xml.etree import ElementTree
 
 from django.test.utils import setup_databases  # type: ignore
 from django.urls import reverse_lazy as reverse
@@ -34,12 +35,12 @@
     SE_IRI,
     setup_django_for,
 )
-from swh.deposit.parsers import parse_xml
 from swh.deposit.tests.common import (
     create_arborescence_archive,
     post_archive,
     post_atom,
 )
+from swh.deposit.utils import NAMESPACES
 from swh.model.hashutil import hash_to_bytes
 from swh.model.swhids import CoreSWHID, ObjectType, QualifiedSWHID
 from swh.scheduler import get_scheduler
@@ -445,8 +446,10 @@
     assert response.status_code == status.HTTP_201_CREATED, response.content.decode()
     from swh.deposit.models import Deposit
 
-    response_content = parse_xml(response.content)
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = ElementTree.fromstring(response.content)
+    deposit_id = int(
+        response_content.findtext("swh:deposit_id", "", namespaces=NAMESPACES)
+    )
     deposit = Deposit._default_manager.get(id=deposit_id)
 
     if deposit.status != deposit_status:
@@ -562,8 +565,8 @@
 
     assert response.status_code == status.HTTP_201_CREATED
 
-    response_content = parse_xml(response.content)
-    deposit_id = response_content["swh:deposit_id"]
+    response_content = ElementTree.fromstring(response.content)
+    deposit_id = int(response_content.findtext("swh:deposit_id", namespaces=NAMESPACES))
     from swh.deposit.models import Deposit
 
     deposit = Deposit._default_manager.get(pk=deposit_id)
diff --git a/swh/deposit/tests/test_client_module.py b/swh/deposit/tests/test_client_module.py
--- a/swh/deposit/tests/test_client_module.py
+++ b/swh/deposit/tests/test_client_module.py
@@ -29,7 +29,7 @@
 
     assert isinstance(result, dict)
 
-    collection = result["app:service"]["app:workspace"]["app:collection"]
+    collection = result["app:service"]["app:workspace"][0]["app:collection"]
     assert collection["sword:name"] == "test"
 
 
diff --git a/swh/deposit/utils.py b/swh/deposit/utils.py
--- a/swh/deposit/utils.py
+++ b/swh/deposit/utils.py
@@ -8,7 +8,6 @@
 from xml.etree import ElementTree
 
 import iso8601
-import xmltodict
 
 from swh.model.exceptions import ValidationError
 from swh.model.model import TimestampWithTimezone
@@ -28,19 +27,6 @@
 }
 
 
-def parse_xml(stream, encoding="utf-8"):
-    data = xmltodict.parse(
-        stream,
-        encoding=encoding,
-        namespaces={uri: prefix for (prefix, uri) in NAMESPACES.items()},
-        process_namespaces=True,
-        dict_constructor=dict,
-    )
-    if "atom:entry" in data:
-        data = data["atom:entry"]
-    return data
-
-
 def normalize_date(date):
     """Normalize date fields as expected by swh workers.