diff --git a/cmd/dd/dd.go b/cmd/dd/dd.go
index 01ae813..0c6a7a9 100644
--- a/cmd/dd/dd.go
+++ b/cmd/dd/dd.go
@@ -10,7 +10,7 @@ import (
 	"strings"
 )
 
-// https://dd.phga.de/dd?usr=<username>&pw=<passwd>
+// https://dd.phga.de/dd?usr=<username>&pwd=<passwd>
 func main() {
 	// cheap routing
 	http.HandleFunc("/dd", handleDynamicUpdate)
@@ -30,7 +30,7 @@ func handleDynamicUpdate(w http.ResponseWriter, r *http.Request) {
 		ip = strings.Split(r.RemoteAddr, ":")[0]
 	}
 
-	if len(up) != 2 {
+	if len(up) != 2 || len(up["usr"]) != 1 || len(up["pwd"]) != 1 {
 		log.Println("Attempted update for:", ip)
 		log.Println("Not enough arguments provided:", up)
 		return