diff --git a/dict.go b/dict.go
index 5197f6d..f1d3a01 100644
--- a/dict.go
+++ b/dict.go
@@ -17,7 +17,7 @@ const (
 )
 
 func main() {
-	if len(os.Args) < 2 {
+	if len(os.Args) < 2 || os.Args[1][0] == '-' {
 		println("usage:", os.Args[0], "word [{de|es|fr|en...}{de|es|fr|en|...}]")
 		return
 	}