diff --git a/lib/RTCSession.js b/lib/RTCSession.js
index 7a1dfd63..5c5c47bd 100644
--- a/lib/RTCSession.js
+++ b/lib/RTCSession.js
@@ -1081,9 +1081,9 @@ module.exports = class RTCSession extends EventEmitter
         return;
       }
 
-      const tone = this._tones[position];
+      const tone = this._tones[0];
 
-      position += 1;
+      this._tones = this._tones.substring(1);
 
       if (tone === ',')
       {