diff --git a/zun/common/docker_image/reference.py b/zun/common/docker_image/reference.py
index 2d5eca1f5..6b27b7207 100644
--- a/zun/common/docker_image/reference.py
+++ b/zun/common/docker_image/reference.py
@@ -72,6 +72,12 @@ class Reference(dict):
         matches = matched.groups()
         if len(matches) != 2:
             return '', name
+        hostname = matches[0]
+        if hostname is None:
+            return '', name
+        if ('.' not in hostname and ':' not in hostname and
+                hostname != 'localhost'):
+            return '', name
 
         return matches[0], matches[1]
 
diff --git a/zun/tests/unit/common/docker_image/test_reference.py b/zun/tests/unit/common/docker_image/test_reference.py
index 729b84cbf..af540cfc9 100644
--- a/zun/tests/unit/common/docker_image/test_reference.py
+++ b/zun/tests/unit/common/docker_image/test_reference.py
@@ -74,7 +74,7 @@ class TestReference(base.BaseTestCase):
             create_test_case(input_='{}a:tag-puts-this-over-max'.
                                     format('a/' * 127),
                              repository='{}a'.format('a/' * 127),
-                             hostname='a',
+                             hostname='',
                              tag='tag-puts-this-over-max'),
             create_test_case(input_='aa/asdf$$^/aa',
                              err=reference.ReferenceInvalidFormat),
@@ -106,12 +106,16 @@ class TestReference(base.BaseTestCase):
                              tag='8080'),
             create_test_case(input_='foo/foo_bar.com:8080',
                              repository='foo/foo_bar.com',
-                             hostname='foo',
+                             hostname='',
                              tag='8080'),
             create_test_case(input_='test.com/foo',
                              repository='test.com/foo',
                              hostname='test.com',
                              path='foo'),
+            create_test_case(input_='test_com/foo',
+                             repository='test_com/foo',
+                             hostname='',
+                             path='test_com/foo'),
             create_test_case(input_='test:8080/foo',
                              repository='test:8080/foo',
                              hostname='test:8080',