diff --git a/swh/web/api/views/origin.py b/swh/web/api/views/origin.py
--- a/swh/web/api/views/origin.py
+++ b/swh/web/api/views/origin.py
@@ -6,6 +6,7 @@
 from distutils.util import strtobool
 from functools import partial
 
+from swh.search.exc import SearchQuerySyntaxError
 from swh.web.api.apidoc import api_doc, format_docstring
 from swh.web.api.apiurls import api_route
 from swh.web.api.utils import (
@@ -194,17 +195,20 @@
     with_visit = request.query_params.get("with_visit", "false")
     visit_type = request.query_params.get("visit_type")
 
-    (results, page_token) = api_lookup(
-        archive.search_origin,
-        url_pattern,
-        bool(strtobool(use_ql)),
-        limit,
-        bool(strtobool(with_visit)),
-        [visit_type] if visit_type else None,
-        page_token,
-        enrich_fn=enrich_origin_search_result,
-        request=request,
-    )
+    try:
+        (results, page_token) = api_lookup(
+            archive.search_origin,
+            url_pattern,
+            bool(strtobool(use_ql)),
+            limit,
+            bool(strtobool(with_visit)),
+            [visit_type] if visit_type else None,
+            page_token,
+            enrich_fn=enrich_origin_search_result,
+            request=request,
+        )
+    except SearchQuerySyntaxError as e:
+        raise BadInputExc(f"Syntax error in search query: {e.args[0]}")
 
     if page_token is not None:
         query_params = {k: v for (k, v) in request.GET.dict().items()}
diff --git a/swh/web/tests/api/views/test_origin.py b/swh/web/tests/api/views/test_origin.py
--- a/swh/web/tests/api/views/test_origin.py
+++ b/swh/web/tests/api/views/test_origin.py
@@ -12,6 +12,7 @@
 from swh.indexer.storage.model import OriginIntrinsicMetadataRow
 from swh.model.hashutil import hash_to_bytes
 from swh.model.model import Origin, OriginVisit, OriginVisitStatus
+from swh.search.exc import SearchQuerySyntaxError
 from swh.search.interface import PagedResult
 from swh.storage.exc import StorageAPIError, StorageDBError
 from swh.storage.utils import now
@@ -557,7 +558,7 @@
         results=ORIGINS, next_page_token=None,
     )
 
-    query = "origin = 'github.com'"
+    query = "origin : 'github.com'"
 
     url = reverse(
         "api-1-origin-search",
@@ -572,6 +573,30 @@
     )
 
 
+def test_api_origin_search_ql_syntax_error(api_client, mocker):
+    mock_archive_search = mocker.patch("swh.web.common.archive.search")
+    mock_archive_search.origin_search.side_effect = SearchQuerySyntaxError(
+        "Invalid syntax"
+    )
+
+    query = "this is not a valid query"
+
+    url = reverse(
+        "api-1-origin-search",
+        url_args={"url_pattern": query},
+        query_params={"visit_type": "git", "use_ql": "true"},
+    )
+    rv = check_api_get_responses(api_client, url, status_code=400)
+    assert rv.data == {
+        "exception": "BadInputExc",
+        "reason": "Syntax error in search query: Invalid syntax",
+    }
+
+    mock_archive_search.origin_search.assert_called_with(
+        query=query, page_token=None, with_visit=False, visit_types=["git"], limit=70
+    )
+
+
 @pytest.mark.parametrize("backend", ["swh-search", "swh-storage"])
 @pytest.mark.parametrize("limit", [1, 2, 3, 10])
 def test_api_origin_search_scroll(api_client, archive_data, mocker, limit, backend):