diff --git a/src/SoundPlayer.js b/src/SoundPlayer.js
index 1a67b7f..ed73a78 100644
--- a/src/SoundPlayer.js
+++ b/src/SoundPlayer.js
@@ -75,12 +75,11 @@ class SoundPlayer {
      * @return {Promise} a Promise that resolves when the sound finishes playing
      */
     finished () {
-        const storedContext = this;
         return new Promise(resolve => {
-            storedContext.bufferSource.onended = function () {
+            this.bufferSource.onended = () => {
                 this.isPlaying = false;
                 resolve();
-            }.bind(storedContext);
+            };
         });
     }
 }