diff --git a/tests/api/test_api.py b/tests/api/test_api.py
index 1f0f6f1..79eecbb 100644
--- a/tests/api/test_api.py
+++ b/tests/api/test_api.py
@@ -803,6 +803,15 @@ async def test_no_extension(
             collections = await client.get("http://test/collections")
             assert collections.status_code == 200, collections.text
 
+            # datetime should be ignored
+            collection_datetime = await client.get(
+                "http://test/collections/test-collection",
+                params={
+                    "datetime": "2000-01-01T00:00:00Z/2000-12-31T00:00:00Z",
+                },
+            )
+            assert collection_datetime.text == collection.text
+
             item = await client.get(
                 "http://test/collections/test-collection/items/test-item"
             )
diff --git a/tests/conftest.py b/tests/conftest.py
index 4ca5c73..fc63514 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -134,7 +134,7 @@ def api_client(request, database):
         FilterExtension(client=FiltersClient()),
         BulkTransactionExtension(client=BulkTransactionsClient()),
     ]
-    collection_extensions = [CollectionSearchExtension()]
+    collection_search_extension = CollectionSearchExtension.from_extensions(extensions)
 
     items_get_request_model = create_request_model(
         model_name="ItemCollectionUri",
@@ -150,13 +150,11 @@ def api_client(request, database):
         extensions, base_model=PgstacSearch
     )
 
-    collections_get_request_model = create_get_request_model(
-        extensions + collection_extensions
-    )
+    collections_get_request_model = collection_search_extension.GET
 
     api = StacApi(
         settings=api_settings,
-        extensions=extensions + collection_extensions,
+        extensions=extensions + [collection_search_extension],
         client=CoreCrudClient(post_request_model=search_post_request_model),
         items_get_request_model=items_get_request_model,
         search_get_request_model=search_get_request_model,