diff --git a/heat/engine/stack.py b/heat/engine/stack.py
index d4c6cf3698..cbffbab34c 100644
--- a/heat/engine/stack.py
+++ b/heat/engine/stack.py
@@ -882,7 +882,7 @@ class Stack(collections.Mapping):
                     exp_trvsl=self.current_traversal)
                 return updated
             else:
-                    stack.update_and_save(values)
+                stack.update_and_save(values)
 
     def _send_notification_and_add_event(self):
         notification.send(self)
@@ -1956,6 +1956,15 @@ class Stack(collections.Mapping):
         sync_point.delete_all(self.context, self.id, self.current_traversal)
 
         if (self.action, self.status) == (self.DELETE, self.COMPLETE):
+            if not self.owner_id:
+                status, reason = self._delete_credentials(
+                    self.status,
+                    self.status_reason,
+                    False)
+                if status == self.FAILED:
+                    # something wrong when delete credentials, set FAILED
+                    self.state_set(self.action, status, reason)
+                    return
             try:
                 stack_object.Stack.delete(self.context, self.id)
             except exception.NotFound:
diff --git a/heat/tests/test_convg_stack.py b/heat/tests/test_convg_stack.py
index 84f9a76aa3..0a29113484 100644
--- a/heat/tests/test_convg_stack.py
+++ b/heat/tests/test_convg_stack.py
@@ -379,6 +379,37 @@ class StackConvergenceCreateUpdateDeleteTest(common.HeatTestCase):
         stack.purge_db()
         self.assertTrue(mock_tmpl_delete.called)
 
+    @mock.patch.object(parser.Stack, '_delete_credentials')
+    @mock.patch.object(stack_object.Stack, 'delete')
+    def test_purge_db_deletes_creds(self, mock_delete_stack,
+                                    mock_creds_delete, mock_cr):
+        stack = tools.get_stack('test_stack', utils.dummy_context(),
+                                template=tools.string_template_five,
+                                convergence=True)
+        reason = 'stack delete complete'
+        mock_creds_delete.return_value = (stack.COMPLETE, reason)
+        stack.state_set(stack.DELETE, stack.COMPLETE, reason)
+        stack.purge_db()
+        self.assertTrue(mock_creds_delete.called)
+        self.assertTrue(mock_delete_stack.called)
+
+    @mock.patch.object(parser.Stack, '_delete_credentials')
+    @mock.patch.object(stack_object.Stack, 'delete')
+    def test_purge_db_deletes_creds_failed(self, mock_delete_stack,
+                                           mock_creds_delete, mock_cr):
+        stack = tools.get_stack('test_stack', utils.dummy_context(),
+                                template=tools.string_template_five,
+                                convergence=True)
+
+        reason = 'stack delete complete'
+        failed_reason = 'Error deleting trust'
+        mock_creds_delete.return_value = (stack.FAILED, failed_reason)
+        stack.state_set(stack.DELETE, stack.COMPLETE, reason)
+        stack.purge_db()
+        self.assertTrue(mock_creds_delete.called)
+        self.assertFalse(mock_delete_stack.called)
+        self.assertEqual((stack.DELETE, stack.FAILED), stack.state)
+
     @mock.patch.object(raw_template_object.RawTemplate, 'delete')
     def test_purge_db_does_not_delete_previous_template_when_stack_fails(
             self, mock_tmpl_delete, mock_cr):