diff --git a/master/buildbot/www/hooks/github.py b/master/buildbot/www/hooks/github.py
index 569dc5094..ffa70a04a 100644
--- a/master/buildbot/www/hooks/github.py
+++ b/master/buildbot/www/hooks/github.py
@@ -244,9 +244,10 @@ class GitHubEventHandler(PullRequestMixin):
         if not match:
             log.msg("Ignoring refname `{}': Not a branch".format(refname))
             return changes
-        category = None  # None is the legacy category for when hook only supported push
-        if match.group(1) == "tags":
-            category = "tag"
+
+        categories = {'heads': 'head', 'tags': 'tag'}
+        # None is the legacy category for when hook only supported push
+        category = categories.get(match.group(1))

         branch = match.group(2)