diff --git a/cmd/clef/main.go b/cmd/clef/main.go
index 7dcd99b4be..dd898871d5 100644
--- a/cmd/clef/main.go
+++ b/cmd/clef/main.go
@@ -545,7 +545,7 @@ func signer(c *cli.Context) error {
 		if err != nil {
 			utils.Fatalf("Could not start RPC api: %v", err)
 		}
-		extapiURL = fmt.Sprintf("http://%v", listener.Addr())
+		extapiURL = fmt.Sprintf("http://%v/", listener.Addr())
 		log.Info("HTTP endpoint opened", "url", extapiURL)
 
 		defer func() {