diff --git a/zuul/connection/gerrit.py b/zuul/connection/gerrit.py
index 05d6534915..6e8d085104 100644
--- a/zuul/connection/gerrit.py
+++ b/zuul/connection/gerrit.py
@@ -63,7 +63,7 @@ class GerritEventConnector(threading.Thread):
         if change:
             event.project_name = change.get('project')
             event.branch = change.get('branch')
-            event.change_number = change.get('number')
+            event.change_number = str(change.get('number'))
             event.change_url = change.get('url')
             patchset = data.get('patchSet')
             if patchset: