diff --git a/roles/koji_hub/files/fedmsg-koji-plugin.py b/roles/koji_hub/files/fedmsg-koji-plugin.py
index 5944017c9c..1ad7787cec 100644
--- a/roles/koji_hub/files/fedmsg-koji-plugin.py
+++ b/roles/koji_hub/files/fedmsg-koji-plugin.py
@@ -148,15 +148,14 @@ def send_message(cbtype, *args, **kws):
     # rhel and fedora.
     problem_fields = ['weight', 'start_ts', 'create_ts', 'completion_ts']
     def scrub(obj):
-        if not isinstance(obj, dict):
-            return
-        for key in obj:
-            if key in problem_fields:
-                del obj[key]
-            if isinstance(obj[key], list):
-                [scrub(item) for item in obj]
-            if isinstance(obj[key], dict):
-                [scrub(obj[key]) for key in obj]
-    scrub(body)
+        if isinstance(obj, list):
+            return [scrub(item) for item in obj]
+        if isinstance(obj, dict):
+            return dict([
+                (k, scrub(v)) for k, v in obj.items() if k not in problem_fields
+            ])
+        return obj
+
+    body = scrub(body)
 
     fedmsg.publish(topic=topic, msg=body, modname='buildsys')