diff --git a/lib/mimelib.js b/lib/mimelib.js
index c49ea02..bf5b900 100644
--- a/lib/mimelib.js
+++ b/lib/mimelib.js
@@ -188,11 +188,11 @@ module.exports.mimeFunctions = {
             result = "";
         
         for(var i=0, len = buffer.length; i<len; i++){
-            if(checkRanges(buffer[i], ranges)){
-                result += String.fromCharCode(buffer[i]);
+            if(checkRanges(buffer.get(i), ranges)){
+                result += String.fromCharCode(buffer.get(i));
                 continue;
             }
-            result += "="+(buffer[i]<0x10?"0":"")+buffer[i].toString(16).toUpperCase();
+            result += "="+(buffer.get(i)<0x10?"0":"")+buffer.get(i).toString(16).toUpperCase();
         }
 
         return result;
@@ -212,11 +212,11 @@ module.exports.mimeFunctions = {
         for(var i=0, len = str.length; i<len; i++){
             chr = str.charAt(i);
             if(chr == "=" && (hex = str.substr(i+1, 2)) && /[\da-fA-F]{2}/.test(hex)){
-                buffer[bufferPos++] = parseInt(hex, 16);
+                buffer.set(bufferPos++, parseInt(hex, 16));
                 i+=2;
                 continue;
             }
-            buffer[bufferPos++] = chr.charCodeAt(0);
+            buffer.set(bufferPos++, chr.charCodeAt(0));
         }
 
         if(fromCharset.toUpperCase().trim() == "BINARY"){