diff --git a/autoflake.py b/autoflake.py
index 67815b0..d4ef466 100755
--- a/autoflake.py
+++ b/autoflake.py
@@ -1574,7 +1574,7 @@
     return exit_status
 
 
-def main():
+def main() -> int:
     """Command-line entry point."""
     try:
         # Exit on broken pipe.