diff --git a/git_cache.py b/git_cache.py
index 1c5a1fe38..0c80ccfa8 100755
--- a/git_cache.py
+++ b/git_cache.py
@@ -439,6 +439,15 @@ class Mirror(object):
             'Git cache has a lot of pack files (%d). Tried to re-bootstrap '
             'but failed. Continuing with non-optimized repository.' %
             len(pack_files))
+    else:
+      # Reset head when refs/remotes/origin/HEAD points to master.
+      # https://crbug.com/1364030
+      origin_head = subprocess.check_output(
+          [self.git_exe, 'symbolic-ref', 'refs/remotes/origin/HEAD'],
+          cwd=self.mirror_path).decode('utf-8', 'ignore').strip()
+
+      if origin_head.endswith('master'):
+        self.RunGit(['remote', 'set-head', '-a', 'origin'])
 
   def _fetch(self,
              rundir,