diff --git a/buildtrigger/bitbuckethandler.py b/buildtrigger/bitbuckethandler.py
index aa840e528..364801e42 100644
--- a/buildtrigger/bitbuckethandler.py
+++ b/buildtrigger/bitbuckethandler.py
@@ -446,6 +446,9 @@ class BitbucketBuildTrigger(BuildTriggerHandler):
     return data
 
   def list_field_values(self, field_name, limit=None):
+    if 'build_source' not in self.config:
+      return None
+
     source = self.config['build_source']
     (namespace, name) = source.split('/')