diff --git a/swh/indexer/codemeta.py b/swh/indexer/codemeta.py
--- a/swh/indexer/codemeta.py
+++ b/swh/indexer/codemeta.py
@@ -3,7 +3,9 @@
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
+import collections
 import csv
+import itertools
 import json
 import os.path
 import re
@@ -127,3 +129,19 @@
     """Same as `pyld.jsonld.expand`, but in the context of CodeMeta."""
     return jsonld.expand(doc,
                          options={'documentLoader': _document_loader})
+
+
+def merge_documents(documents):
+    """Takes a list of metadata dicts, each generated from a different
+    metadata file, and merges them.
+
+    Removes duplicates, if any."""
+    documents = list(itertools.chain.from_iterable(map(expand, documents)))
+    merged_document = collections.defaultdict(list)
+    for document in documents:
+        for (key, values) in document.items():
+            for value in values:
+                if value not in merged_document[key]:
+                    merged_document[key].append(value)
+
+    return compact(merged_document)
diff --git a/swh/indexer/metadata.py b/swh/indexer/metadata.py
--- a/swh/indexer/metadata.py
+++ b/swh/indexer/metadata.py
@@ -7,11 +7,11 @@
 
 from swh.core.utils import grouper
 
+from swh.indexer.codemeta import merge_documents
 from swh.indexer.indexer import ContentIndexer, RevisionIndexer, OriginIndexer
 from swh.indexer.origin_head import OriginHeadIndexer
 from swh.indexer.metadata_dictionary import MAPPINGS
 from swh.indexer.metadata_detector import detect_metadata
-from swh.indexer.metadata_detector import extract_minimal_metadata_dict
 from swh.indexer.storage import INDEXER_CFG_KEY
 
 from swh.model import hashutil
@@ -263,9 +263,8 @@
                     self.log.exception(
                         "Exception while indexing metadata on contents")
 
-        # transform metadata into min set with swh-metadata-detector
-        min_metadata = extract_minimal_metadata_dict(metadata)
-        return (used_mappings, min_metadata)
+        metadata = merge_documents(metadata)
+        return (used_mappings, metadata)
 
 
 class OriginMetadataIndexer(OriginIndexer):
diff --git a/swh/indexer/metadata_detector.py b/swh/indexer/metadata_detector.py
--- a/swh/indexer/metadata_detector.py
+++ b/swh/indexer/metadata_detector.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 swh.indexer.codemeta import compact, expand
-from swh.indexer.codemeta import make_absolute_uri
 from swh.indexer.metadata_dictionary import MAPPINGS
 
 
@@ -24,39 +22,3 @@
         if matches:
             results[mapping_name] = matches
     return results
-
-
-_MINIMAL_PROPERTY_SET = {
-    "developmentStatus", "version", "operatingSystem", "description",
-    "keywords", "issueTracker", "name", "author", "relatedLink",
-    "url", "license", "maintainer", "email", "identifier",
-    "codeRepository"}
-
-MINIMAL_METADATA_SET = {make_absolute_uri(prop)
-                        for prop in _MINIMAL_PROPERTY_SET}
-
-
-def extract_minimal_metadata_dict(metadata_list):
-    """
-    Every item in the metadata_list is a dict of translated_metadata in the
-    CodeMeta vocabulary.
-
-    We wish to extract a minimal set of terms and keep all values corresponding
-    to this term without duplication.
-
-    Args:
-        metadata_list (list): list of dicts of translated_metadata
-
-    Returns:
-        dict: minimal_dict; dict with selected values of metadata
-    """
-    minimal_dict = {}
-    for document in metadata_list:
-        for metadata_item in expand(document):
-            for (term, value) in metadata_item.items():
-                if term in MINIMAL_METADATA_SET:
-                    if term not in minimal_dict:
-                        minimal_dict[term] = [value]
-                    elif value not in minimal_dict[term]:
-                        minimal_dict[term].append(value)
-    return compact(minimal_dict)
diff --git a/swh/indexer/tests/test_metadata.py b/swh/indexer/tests/test_metadata.py
--- a/swh/indexer/tests/test_metadata.py
+++ b/swh/indexer/tests/test_metadata.py
@@ -11,10 +11,11 @@
 from swh.model.hashutil import hash_to_bytes
 
 from swh.indexer.codemeta import CODEMETA_TERMS, CROSSWALK_TABLE
+from swh.indexer.codemeta import merge_documents
 from swh.indexer.metadata_dictionary import MAPPINGS
 from swh.indexer.metadata_dictionary.base import merge_values
 from swh.indexer.metadata_detector import (
-    detect_metadata, extract_minimal_metadata_dict
+    detect_metadata
 )
 from swh.indexer.metadata import (
     ContentMetadataIndexer, RevisionMetadataIndexer
@@ -184,7 +185,7 @@
         # then
         self.assertEqual(declared_metadata, result)
 
-    def test_extract_minimal_metadata_dict(self):
+    def test_merge_documents(self):
         """
         Test the creation of a coherent minimal metadata set
         """
@@ -211,7 +212,7 @@
         }]
 
         # when
-        results = extract_minimal_metadata_dict(metadata_list)
+        results = merge_documents(metadata_list)
 
         # then
         expected_results = {
diff --git a/swh/indexer/tests/utils.py b/swh/indexer/tests/utils.py
--- a/swh/indexer/tests/utils.py
+++ b/swh/indexer/tests/utils.py
@@ -407,6 +407,7 @@
         'https://github.com/librariesio/yarn-parser/issues',
     'name': 'yarn-parser',
     'keywords': ['yarn', 'parse', 'lock', 'dependencies'],
+    'type': 'SoftwareSourceCode',
 }