diff --git a/tools/license_header.py b/tools/license_header.py
index f6dd1cc6f883..41abb3e476d1 100755
--- a/tools/license_header.py
+++ b/tools/license_header.py
@@ -181,7 +181,7 @@ def under_git():
 
 def git_files():
     return list(map(os.fsdecode,
-        subprocess.check_output('git ls-tree -r master --name-only -z'.split()).split(b'\0')))
+        subprocess.check_output('git ls-tree -r HEAD --name-only -z'.split()).split(b'\0')))
 
 
 def file_generator(path: str):