diff --git a/doc/api_samples/os-aggregates/aggregates-metadata-post-resp.json b/doc/api_samples/os-aggregates/aggregates-metadata-post-resp.json
index 83bf953f0..bcfeacd8f 100644
--- a/doc/api_samples/os-aggregates/aggregates-metadata-post-resp.json
+++ b/doc/api_samples/os-aggregates/aggregates-metadata-post-resp.json
@@ -11,6 +11,6 @@
             "key": "value"
         },
         "name": "name",
-        "updated_at": null
+        "updated_at": "2013-08-18T12:17:55.986540"
     }
 }
diff --git a/nova/tests/functional/api_sample_tests/api_samples/os-aggregates/aggregates-metadata-post-resp.json.tpl b/nova/tests/functional/api_sample_tests/api_samples/os-aggregates/aggregates-metadata-post-resp.json.tpl
index b15c40fa5..98bf8bb63 100644
--- a/nova/tests/functional/api_sample_tests/api_samples/os-aggregates/aggregates-metadata-post-resp.json.tpl
+++ b/nova/tests/functional/api_sample_tests/api_samples/os-aggregates/aggregates-metadata-post-resp.json.tpl
@@ -11,6 +11,6 @@
             "key": "value"
         },
         "name": "name",
-        "updated_at": null
+        "updated_at": %(strtime)s
     }
 }