diff --git a/endpoints/trigger.py b/endpoints/trigger.py
index 8a844a13c..ab7aa9065 100644
--- a/endpoints/trigger.py
+++ b/endpoints/trigger.py
@@ -315,7 +315,7 @@ class GithubBuildTrigger(BuildTrigger):
 
   def handle_trigger_request(self, request, auth_token, config):
     payload = request.get_json()
-    if not payload or not 'head_commit' in payload:
+    if not payload or payload.get('head_commit') is None:
       raise SkipRequestException()
     
     if 'zen' in payload: