diff --git a/zuul/ansible/callback/zuul_stream.py b/zuul/ansible/callback/zuul_stream.py
index 34d4406..a9c1155 100644
--- a/zuul/ansible/callback/zuul_stream.py
+++ b/zuul/ansible/callback/zuul_stream.py
@@ -326,7 +326,7 @@
             # We have a custom zuul module that doesn't want the parameters
             # from its returned splatted to stdout. This is typically for
             # modules that are collecting data to be displayed some other way.
-            for key in result_dict.keys():
+            for key in list(result_dict.keys()):
                 if key != 'changed':
                     result_dict.pop(key)