diff --git a/connection.c b/connection.c
--- a/connection.c
+++ b/connection.c
@@ -55,7 +55,7 @@
 
     if (argc != 3) {
         printf ("Usage: %s <ipaddr> <port>\n", argv[0]);
-        return EXIT_SUCCESS;
+        return EXIT_FAILURE;
     }
 
     if ((sockfd = connection (argv[1], atoi (argv[2]))) < 0) {