--- a/lotto.c
+++ b/lotto.c
@@ -184,7 +184,7 @@
             printf ("       -n: n-numbers from [1..end]\n");
             printf ("       -v: verbose output\n");
             printf ("       -w: verbose and wide output\n");
-            return 0;
+            return EXIT_SUCCESS;
         }
     }