diff --git a/swift/common/middleware/swift3.py b/swift/common/middleware/swift3.py
index aab8dde0d8..8d67655c59 100644
--- a/swift/common/middleware/swift3.py
+++ b/swift/common/middleware/swift3.py
@@ -267,7 +267,7 @@ class BucketController(Controller):
                 'true' if len(objects) == (max_keys + 1) else 'false',
                 max_keys,
                 xml_escape(self.container_name),
-                "".join(['<Contents><Key>%s</Key><LastModified>%s</LastModif'\
+                "".join(['<Contents><Key>%s</Key><LastModified>%sZ</LastModif'\
                         'ied><ETag>%s</ETag><Size>%s</Size><StorageClass>STA'\
                         'NDARD</StorageClass></Contents>' %
                         (xml_escape(i['name']), i['last_modified'], i['hash'],
diff --git a/test/unit/common/middleware/test_swift3.py b/test/unit/common/middleware/test_swift3.py
index 2579cce83d..da49413310 100644
--- a/test/unit/common/middleware/test_swift3.py
+++ b/test/unit/common/middleware/test_swift3.py
@@ -286,6 +286,9 @@ class TestSwift3(unittest.TestCase):
         for o in objects:
             if o.childNodes[0].nodeName == 'Key':
                 names.append(o.childNodes[0].childNodes[0].nodeValue)
+            if o.childNodes[1].nodeName == 'LastModified':
+                self.assertTrue(
+                    o.childNodes[1].childNodes[0].nodeValue.endswith('Z'))
 
         self.assertEquals(len(names), len(FakeAppBucket().objects))
         for i in FakeAppBucket().objects: