diff --git a/transport/internet/websocket/dialer.go b/transport/internet/websocket/dialer.go
index 67f159b1..6a06a67e 100644
--- a/transport/internet/websocket/dialer.go
+++ b/transport/internet/websocket/dialer.go
@@ -120,7 +120,8 @@ func dialWebSocket(ctx context.Context, dest net.Destination, streamSettings *in
 
 	header := wsSettings.GetRequestHeader()
 	if ed != nil {
-		header.Set("Sec-WebSocket-Protocol", base64.StdEncoding.EncodeToString(ed))
+		// RawURLEncoding is support by both V2Ray/V2Fly and XRay.
+		header.Set("Sec-WebSocket-Protocol", base64.RawURLEncoding.EncodeToString(ed))
 	}
 
 	conn, resp, err := dialer.Dial(uri, header)