--- a/testcase.c
+++ b/testcase.c
@@ -16,7 +16,7 @@
 
     if (argc != 4) {
         printf ("Usage: %s (char*)string (char*)delim1 (char*)delim2\n", argv[0]);
-        return 0;
+        return EXIT_FAILURE;
     }
 
     snprintf (line, 80, "%s\r\n", argv[1]);