diff --git a/optipdf b/optipdf
index 7aca076..9755940 100755
--- a/optipdf
+++ b/optipdf
@@ -102,7 +102,7 @@ TEMP_DIR=
 
 if [[ ${#FILES[@]} -eq 0 ]]; then
     USAGE >&2
-    exit 1
+    exit 2
 fi
 
 file_size() {