diff --git a/update.py b/update.py
index b896f4d..b805281 100755
--- a/update.py
+++ b/update.py
@@ -78,7 +78,7 @@ def main():
         return
 
     subprocess.run(['hub', 'add', *filenames], check=True)
-    diff = subprocess.run(['hub', 'diff', '--stat', '--cached', *filenames],
+    diff = subprocess.run(['hub', 'diff', '--stat', '--cached', '*.json'],
                           check=True,
                           stdout=subprocess.PIPE,
                           encoding='utf-8').stdout