diff --git a/bytebeat_compiler.py b/bytebeat_compiler.py
index b3652fb..f72bb92 100644
--- a/bytebeat_compiler.py
+++ b/bytebeat_compiler.py
@@ -195,6 +195,7 @@ if __name__ == "__main__":
 
 	if args.mode != "sequential" and args.mode != "instant":
 		print("Invalid mode '%s'" % args.mode)
+		raise SystemExit
 
 	rewrite_file(PATHS["substitute"], substitute_vars({
 		"bytebeat_contents": bytebeat_contents,