diff --git a/chord_metadata_service/authz/tests/helpers.py b/chord_metadata_service/authz/tests/helpers.py
index ccb70d861..9ec625723 100644
--- a/chord_metadata_service/authz/tests/helpers.py
+++ b/chord_metadata_service/authz/tests/helpers.py
@@ -76,6 +76,17 @@ def one_no_authz_put(self, url: str, *args, **kwargs):
         """
         return self._one_authz_put(False, url, *args, **kwargs)
 
+    def _one_authz_patch(self, authz_res: bool, url: str, *args, **kwargs):
+        with aioresponses() as m:
+            mock_authz_eval_one_result(m, authz_res)
+            return self.client.patch(url, *args, content_type="application/json", **kwargs)
+
+    def one_authz_patch(self, url: str, *args, **kwargs):
+        """
+        Mocks a single True response from the authorization service and executes a JSON PATCH request.
+        """
+        return self._one_authz_patch(True, url, *args, **kwargs)
+
     def _one_authz_delete(self, authz_res: bool, url: str, *args, **kwargs):
         with aioresponses() as m:
             mock_authz_eval_one_result(m, authz_res)
diff --git a/chord_metadata_service/chord/api_views.py b/chord_metadata_service/chord/api_views.py
index 16c3495dd..8038dce89 100644
--- a/chord_metadata_service/chord/api_views.py
+++ b/chord_metadata_service/chord/api_views.py
@@ -251,7 +251,7 @@ async def update(self, request, *args, **kwargs):
             return forbidden(request)  # side effect: sets authz done flag
 
         # Do not allow datasets to change project
-        if request.data["project"] != dataset_project_id:
+        if "project" in request.data and request.data["project"] != dataset_project_id:
             return bad_request(request, "Dataset project ID cannot change")
 
         authz.mark_authz_done(request)
diff --git a/chord_metadata_service/chord/tests/test_api.py b/chord_metadata_service/chord/tests/test_api.py
index d5be94229..d50391001 100644
--- a/chord_metadata_service/chord/tests/test_api.py
+++ b/chord_metadata_service/chord/tests/test_api.py
@@ -236,9 +236,17 @@ def setUp(self):
 
     def test_update_dataset(self):
         r = self.one_authz_put(f"/api/datasets/{self.dataset.identifier}", data=json.dumps(self.valid_update))
-        assert r.status_code == status.HTTP_200_OK
+        self.assertEqual(r.status_code, status.HTTP_200_OK)
+        self.dataset.refresh_from_db()
+        self.assertEqual(self.dataset.title, self.valid_update["title"])
+
+    def test_update_dataset_partial(self):
+        r = self.one_authz_patch(
+            f"/api/datasets/{self.dataset.identifier}", data=json.dumps({"title": self.valid_update["title"]})
+        )
+        self.assertEqual(r.status_code, status.HTTP_200_OK)
         self.dataset.refresh_from_db()
-        assert self.dataset.title == self.valid_update["title"]
+        self.assertEqual(self.dataset.title, self.valid_update["title"])
 
     def test_update_dataset_changed_project(self):
         r = self.one_authz_put(
@@ -248,50 +256,53 @@ def test_update_dataset_changed_project(self):
                 "project": str(self.project_2.identifier),
             })
         )
-        assert r.status_code == status.HTTP_400_BAD_REQUEST
+        self.assertEqual(r.status_code, status.HTTP_400_BAD_REQUEST)
         res = r.json()
-        assert res["message"] == "Bad Request"
-        assert res["errors"][0]["message"] == "Dataset project ID cannot change"
+        self.assertEqual(res["message"], "Bad Request")
+        self.assertEqual(res["errors"][0]["message"], "Dataset project ID cannot change")
 
     def test_update_dataset_bad_dats_json(self):
         r = self.one_authz_put(
             f"/api/datasets/{self.dataset.identifier}",
             data=json.dumps({**self.valid_update, "dats_file": "asdf"}),  # asdf is not JSON
         )
-        assert r.status_code == status.HTTP_400_BAD_REQUEST
+        self.assertEqual(r.status_code, status.HTTP_400_BAD_REQUEST)
         res = r.json()
-        assert res["message"] == "Bad Request"
-        assert res["errors"][0]["message"] == (
-            "Submitted dataset.dats_file data is not a valid JSON string. Make sure the string value is JSON "
-            "compatible, or submit dats_file as a JSON object."
+        self.assertEqual(res["message"], "Bad Request")
+        self.assertEqual(
+            res["errors"][0]["message"],
+            (
+                "Submitted dataset.dats_file data is not a valid JSON string. Make sure the string value is JSON "
+                "compatible, or submit dats_file as a JSON object."
+            )
         )
 
     def test_update_dataset_forbidden(self):
         r = self.one_no_authz_put(f"/api/datasets/{self.dataset.identifier}", data=json.dumps(self.valid_update))
-        assert r.status_code == status.HTTP_403_FORBIDDEN
+        self.assertEqual(r.status_code, status.HTTP_403_FORBIDDEN)
 
     def test_update_dataset_not_found(self):
         r = self.one_authz_put(f"/api/datasets/{uuid.uuid4()}", data=json.dumps(self.valid_update))
-        assert r.status_code == status.HTTP_404_NOT_FOUND
+        self.assertEqual(r.status_code, status.HTTP_404_NOT_FOUND)
 
 
 class DeleteDatasetTest(AuthzAPITestCase, ProjectTestCase):
 
     def test_delete_dataset(self):
         r = self.one_authz_delete(f"/api/datasets/{self.dataset.identifier}")
-        assert r.status_code == status.HTTP_204_NO_CONTENT
+        self.assertEqual(r.status_code, status.HTTP_204_NO_CONTENT)
 
         with self.assertRaises(Dataset.DoesNotExist):  # must not exist in DB anymore
             self.dataset.refresh_from_db()
 
     def test_delete_dataset_forbidden(self):
         r = self.one_no_authz_delete(f"/api/datasets/{self.dataset.identifier}")
-        assert r.status_code == status.HTTP_403_FORBIDDEN
+        self.assertEqual(r.status_code, status.HTTP_403_FORBIDDEN)
         self.dataset.refresh_from_db()  # must not raise DoesNotExist
 
     def test_delete_dataset_not_found(self):
         r = self.client.delete(f"/api/datasets/{uuid.uuid4()}")
-        assert r.status_code == status.HTTP_404_NOT_FOUND
+        self.assertEqual(r.status_code, status.HTTP_404_NOT_FOUND)
 
 
 class CreateProjectJsonSchema(AuthzAPITestCaseWithProjectJSON):