diff --git a/tools/distrib/check_copyright.py b/tools/distrib/check_copyright.py
index 68411c6..4577ab3 100755
--- a/tools/distrib/check_copyright.py
+++ b/tools/distrib/check_copyright.py
@@ -71,6 +71,7 @@
 # that given a line of license text, returns what should
 # be in the file
 LICENSE_PREFIX = {
+  '.bat':       r'@rem\s*',
   '.c':         r'\s*(?://|\*)\s*',
   '.cc':        r'\s*(?://|\*)\s*',
   '.h':         r'\s*(?://|\*)\s*',