diff --git a/Blob.js b/Blob.js
index 76a6c0b..100fefb 100644
--- a/Blob.js
+++ b/Blob.js
@@ -166,7 +166,7 @@
       return view
     }
     function encodeByteArray(input) {
-      var byteToCharMap = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789'
+      var byteToCharMap = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
 
       var output = [];