diff --git a/driver/Mcltt.ml b/driver/Mcltt.ml
index b3ebaa5..29ca6d2 100644
--- a/driver/Mcltt.ml
+++ b/driver/Mcltt.ml
@@ -5,7 +5,7 @@ let () =
   then begin
     Printf.fprintf stderr
       "Missing <input-file> argument.\nUsage: %s <input-file>\n" Sys.argv.(0);
-    exit 5
+    exit 7
   end;
   let filename = Sys.argv.(1) in
   let code = main_of_filename filename in