diff --git a/main.go b/main.go
index 69ca06e..cddb5ea 100644
--- a/main.go
+++ b/main.go
@@ -15,7 +15,7 @@ import (
 
 var (
 	imgServer  = flag.String("s", "https://images.example.com/", "URL prefix")
-	listenAddr = flag.Int("l", "0.0.0.0:8080", "Listen address")
+	listenAddr = flag.String("l", "0.0.0.0:8080", "Listen address")
 )
 
 func init() {