diff --git a/git_map_branches.py b/git_map_branches.py
index c00dcb95e..b889b454d 100755
--- a/git_map_branches.py
+++ b/git_map_branches.py
@@ -270,7 +270,7 @@ class BranchMapper(object):
 
     # The subject of the most recent commit on the branch.
     if self.show_subject:
-      line.append(run('log', '-n1', '--format=%s', branch))
+      line.append(run('log', '-n1', '--format=%s', branch, '--'))
 
     self.output.append(line)