diff --git a/endpoints/trigger.py b/endpoints/trigger.py
index 45b286203..1a07a357a 100644
--- a/endpoints/trigger.py
+++ b/endpoints/trigger.py
@@ -526,7 +526,7 @@ class BitbucketBuildTrigger(BuildTriggerHandler):
     branch_name = run_parameters.get('branch_name')
     (result, data, _) = repository.get_main_branch()
     if result:
-      branch_name = data['name'] or branch_name
+      branch_name = branch_name or data['name']
 
     # Lookup the commit SHA for the branch.
     (result, data, _) = repository.get_branches()