diff --git a/zun/compute/manager.py b/zun/compute/manager.py
index dc3d4eeb5..3218bccaa 100644
--- a/zun/compute/manager.py
+++ b/zun/compute/manager.py
@@ -984,7 +984,9 @@ class Manager(periodic_task.PeriodicTasks):
 
     def _do_image_pull(self, context, image):
         LOG.debug('Creating image...')
-        repo_tag = image.repo + ":" + image.tag
+        repo_tag = image.repo
+        if image.tag:
+            repo_tag += ":" + image.tag
         try:
             pulled_image, image_loaded = self.driver.pull_image(
                 context, image.repo, image.tag)
diff --git a/zun/tests/unit/compute/test_compute_manager.py b/zun/tests/unit/compute/test_compute_manager.py
index 7990e505f..58a53e217 100644
--- a/zun/tests/unit/compute/test_compute_manager.py
+++ b/zun/tests/unit/compute/test_compute_manager.py
@@ -1130,6 +1130,19 @@ class TestManager(base.TestCase):
         mock_inspect.assert_called_once_with(repo_tag)
         mock_load.assert_called_once_with(ret['path'])
 
+    @mock.patch.object(fake_driver, 'inspect_image')
+    @mock.patch.object(Image, 'save')
+    @mock.patch.object(fake_driver, 'pull_image')
+    def test_image_pull_tag_is_none(self, mock_pull, mock_save, mock_inspect):
+        image = Image(self.context, **utils.get_test_image(tag=None))
+        ret = {'image': 'repo', 'path': 'out_path', 'driver': 'glance'}
+        mock_pull.return_value = ret, True
+        mock_inspect.return_value = {'Id': 'fake-id', 'Size': 512}
+        self.compute_manager._do_image_pull(self.context, image)
+        mock_pull.assert_any_call(self.context, image.repo, image.tag)
+        mock_save.assert_called_once()
+        mock_inspect.assert_called_once_with(image.repo)
+
     @mock.patch.object(fake_driver, 'execute_resize')
     def test_container_exec_resize(self, mock_resize):
         self.compute_manager.container_exec_resize(