diff --git a/nova/scheduler/utils.py b/nova/scheduler/utils.py
index 25a436dd4592..c6d7d053dc7c 100644
--- a/nova/scheduler/utils.py
+++ b/nova/scheduler/utils.py
@@ -1014,11 +1014,12 @@ def claim_resources(ctx, client, spec_obj, instance_uuid, alloc_req,
 
     project_id = spec_obj.project_id
 
-    # NOTE(jaypipes): So, the RequestSpec doesn't store the user_id,
-    # only the project_id, so we need to grab the user information from
-    # the context. Perhaps we should consider putting the user ID in
-    # the spec object?
-    user_id = ctx.user_id
+    # We didn't start storing the user_id in the RequestSpec until Rocky so
+    # if it's not set on an old RequestSpec, use the user_id from the context.
+    if 'user_id' in spec_obj and spec_obj.user_id:
+        user_id = spec_obj.user_id
+    else:
+        user_id = ctx.user_id
 
     # NOTE(gibi): this could raise AllocationUpdateFailed which means there is
     # a serious issue with the instance_uuid as a consumer. Every caller of
diff --git a/nova/tests/unit/scheduler/test_utils.py b/nova/tests/unit/scheduler/test_utils.py
index 439469aede63..c96da46fa326 100644
--- a/nova/tests/unit/scheduler/test_utils.py
+++ b/nova/tests/unit/scheduler/test_utils.py
@@ -881,8 +881,8 @@ class TestUtils(test.NoDBTestCase):
         call the placement client to claim resources for the instance.
         """
         mock_is_rebuild.return_value = False
-        ctx = mock.Mock(user_id=uuids.user_id)
-        spec_obj = mock.Mock(project_id=uuids.project_id)
+        ctx = nova_context.RequestContext(user_id=uuids.user_id)
+        spec_obj = objects.RequestSpec(project_id=uuids.project_id)
         instance_uuid = uuids.instance
         alloc_req = mock.sentinel.alloc_req
         mock_client.claim_resources.return_value = True
@@ -896,6 +896,16 @@ class TestUtils(test.NoDBTestCase):
             consumer_generation=None)
         self.assertTrue(res)
 
+        # Now do it again but with RequestSpec.user_id set.
+        spec_obj.user_id = uuids.spec_user_id
+        mock_client.reset_mock()
+        utils.claim_resources(ctx, mock_client, spec_obj, instance_uuid,
+                              alloc_req)
+        mock_client.claim_resources.assert_called_once_with(
+            ctx, uuids.instance, mock.sentinel.alloc_req, uuids.project_id,
+            uuids.spec_user_id, allocation_request_version=None,
+            consumer_generation=None)
+
     @mock.patch('nova.scheduler.client.report.SchedulerReportClient')
     @mock.patch('nova.scheduler.utils.request_is_rebuild')
     def test_claim_resouces_for_policy_check(self, mock_is_rebuild,