diff --git a/accounts/external/backend.go b/accounts/external/backend.go
index 3e57aa8f13..c751e82d4a 100644
--- a/accounts/external/backend.go
+++ b/accounts/external/backend.go
@@ -1,3 +1,19 @@
+// Copyright 2018 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+
 package external
 
 import (
@@ -53,7 +69,7 @@ type ExternalSigner struct {
 }
 
 func NewExternalSigner(endpoint string) (*ExternalSigner, error) {
-	client, err := rpc.DialHTTP(endpoint)
+	client, err := rpc.Dial(endpoint)
 	if err != nil {
 		return nil, err
 	}