diff --git a/swift3/controllers/obj.py b/swift3/controllers/obj.py
index 3d040f5f..7cbf73b1 100644
--- a/swift3/controllers/obj.py
+++ b/swift3/controllers/obj.py
@@ -102,8 +102,10 @@ class ObjectController(Controller):
             resp.append_copy_resp_body(req.controller_name,
                                        last_modified)
 
-            resp.headers = {key: value for (key, value) in resp.headers.items()
-                            if not key.startswith('x-amz-meta-')}
+            # delete object metadata from response
+            for key in list(resp.headers.keys()):
+                if key.startswith('x-amz-meta-'):
+                    del resp.headers[key]
 
         resp.status = HTTP_OK
         return resp