diff --git a/openstackclient/image/v2/image.py b/openstackclient/image/v2/image.py
index d793c4599b..0b8647a0ca 100644
--- a/openstackclient/image/v2/image.py
+++ b/openstackclient/image/v2/image.py
@@ -1024,9 +1024,7 @@ class UnsetImage(command.Command):
 
         if parsed_args.properties:
             for k in parsed_args.properties:
-                try:
-                    assert(k in image.keys())
-                except AssertionError:
+                if k not in image:
                     LOG.error(_("property unset failed, '%s' is a "
                                 "nonexistent property "), k)
                     propret += 1