diff --git a/openstackclient/identity/v3/tag.py b/openstackclient/identity/v3/tag.py
index 7a93218667..ce1dfe8919 100644
--- a/openstackclient/identity/v3/tag.py
+++ b/openstackclient/identity/v3/tag.py
@@ -129,7 +129,7 @@ def update_tags_in_args(parsed_args, obj, args):
         args['tags'] = []
         obj.tags = []
     if parsed_args.remove_tag:
-        args['tags'] = list(set(obj.tags) - set(parsed_args.remove_tag))
+        args['tags'] = sorted(set(obj.tags) - set(parsed_args.remove_tag))
         return
     if parsed_args.tags:
-        args['tags'] = list(set(obj.tags).union(set(parsed_args.tags)))
+        args['tags'] = sorted(set(obj.tags).union(set(parsed_args.tags)))
diff --git a/openstackclient/tests/unit/identity/v3/test_project.py b/openstackclient/tests/unit/identity/v3/test_project.py
index d9427e37c8..ffef854e92 100644
--- a/openstackclient/tests/unit/identity/v3/test_project.py
+++ b/openstackclient/tests/unit/identity/v3/test_project.py
@@ -1130,7 +1130,7 @@ class TestProjectSet(TestProject):
         # Set expected values. new tag is added to original tags for update.
         kwargs = {
             'name': 'qwerty',
-            'tags': list(set(['tag1', 'tag2', 'tag3', 'foo'])),
+            'tags': sorted(set(['tag1', 'tag2', 'tag3', 'foo'])),
         }
         # ProjectManager.update(project, name=, domain=, description=,
         #                       enabled=, **kwargs)