diff --git a/lib/transports/polling-xhr.js b/lib/transports/polling-xhr.js
index dbf000f43..297bac59e 100755
--- a/lib/transports/polling-xhr.js
+++ b/lib/transports/polling-xhr.js
@@ -205,11 +205,6 @@ Request.prototype.create = function () {
         }
       }
     } catch (e) {}
-    if (this.supportsBinary) {
-      // This has to be done after open because Firefox is stupid
-      // http://stackoverflow.com/questions/13216903/get-binary-data-with-xmlhttprequest-in-a-firefox-extension
-      xhr.responseType = 'arraybuffer';
-    }
 
     if ('POST' === this.method) {
       try {
@@ -243,6 +238,15 @@ Request.prototype.create = function () {
       };
     } else {
       xhr.onreadystatechange = function () {
+        if (xhr.readyState === 2) {
+          var contentType;
+          try {
+            contentType = xhr.getResponseHeader('Content-Type');
+          } catch (e) {}
+          if (contentType === 'application/octet-stream') {
+            xhr.responseType = 'arraybuffer';
+          }
+        }
         if (4 !== xhr.readyState) return;
         if (200 === xhr.status || 1223 === xhr.status) {
           self.onLoad();
@@ -348,26 +352,12 @@ Request.prototype.onLoad = function () {
   try {
     var contentType;
     try {
-      contentType = this.xhr.getResponseHeader('Content-Type').split(';')[0];
+      contentType = this.xhr.getResponseHeader('Content-Type');
     } catch (e) {}
     if (contentType === 'application/octet-stream') {
       data = this.xhr.response || this.xhr.responseText;
     } else {
-      if (!this.supportsBinary) {
-        data = this.xhr.responseText;
-      } else {
-        try {
-          data = String.fromCharCode.apply(null, new Uint8Array(this.xhr.response));
-        } catch (e) {
-          var ui8Arr = new Uint8Array(this.xhr.response);
-          var dataArray = [];
-          for (var idx = 0, length = ui8Arr.length; idx < length; idx++) {
-            dataArray.push(ui8Arr[idx]);
-          }
-
-          data = String.fromCharCode.apply(null, dataArray);
-        }
-      }
+      data = this.xhr.responseText;
     }
   } catch (e) {
     this.onError(e);
diff --git a/lib/transports/polling.js b/lib/transports/polling.js
index e600af601..22e0ed0e7 100644
--- a/lib/transports/polling.js
+++ b/lib/transports/polling.js
@@ -145,7 +145,7 @@ Polling.prototype.onData = function (data) {
   };
 
   // decode payload
-  parser.decodePayload(data, this.socket.binaryType, this.supportsBinary, callback);
+  parser.decodePayload(data, this.socket.binaryType, false, callback);
 
   // if an event did not trigger closing
   if ('closed' !== this.readyState) {