diff --git a/hpot.go b/hpot.go
index 39c3952..4964764 100644
--- a/hpot.go
+++ b/hpot.go
@@ -119,7 +119,7 @@ func Main() int {
 	flag.Parse()
 	if len(flag.Args()) == 0 {
 		fmt.Println(usage)
-		return 0
+		return 1
 	}
 
 	ports, err := parsePorts(flag.Args()[0])