diff --git a/4chan_x.user.js b/4chan_x.user.js
index 592a2d146..eb4452cca 100644
--- a/4chan_x.user.js
+++ b/4chan_x.user.js
@@ -331,14 +331,15 @@
       return fd;
     },
     ajax: function(url, callbacks, opts) {
-      var form, headers, key, r, type, upCallbacks, val;
+      var form, headers, key, r, responseType, type, upCallbacks, val;
       if (opts == null) {
         opts = {};
       }
-      type = opts.type, headers = opts.headers, upCallbacks = opts.upCallbacks, form = opts.form;
+      type = opts.type, responseType = opts.responseType, headers = opts.headers, upCallbacks = opts.upCallbacks, form = opts.form;
       r = new XMLHttpRequest();
       type || (type = form && 'post' || 'get');
       r.open(type, url, true);
+      r.responseType = $.engine === 'presto' && responseType === 'document' ? '' : responseType || '';
       for (key in headers) {
         val = headers[key];
         r.setRequestHeader(key, val);
@@ -2617,8 +2618,12 @@
           return;
         }
         Updater.lastModified = this.getResponseHeader('Last-Modified');
-        doc = d.implementation.createHTMLDocument('');
-        doc.documentElement.innerHTML = this.response;
+        if ($.engine === 'presto') {
+          doc = d.implementation.createHTMLDocument('');
+          doc.documentElement.innerHTML = this.response;
+        } else {
+          doc = this.response;
+        }
         lastPost = Updater.thread.lastElementChild;
         id = lastPost.id.slice(2);
         nodes = [];
@@ -2670,6 +2675,7 @@
       return Updater.request = $.ajax(url, {
         onload: Updater.cb.update
       }, {
+        responseType: 'document',
         headers: {
           'If-Modified-Since': Updater.lastModified
         }
diff --git a/script.coffee b/script.coffee
index 6d2374bb6..07b9bd8f9 100644
--- a/script.coffee
+++ b/script.coffee
@@ -274,10 +274,15 @@ $.extend $,
         fd.append key, val if val
     fd
   ajax: (url, callbacks, opts={}) ->
-    {type, headers, upCallbacks, form} = opts
+    {type, responseType, headers, upCallbacks, form} = opts
     r = new XMLHttpRequest()
     type or= form and 'post' or 'get'
     r.open type, url, true
+    r.responseType =
+      if $.engine is 'presto' and responseType is 'document'
+        ''
+      else
+        responseType or ''
     for key, val of headers
       r.setRequestHeader key, val
     $.extend r, callbacks
@@ -2058,8 +2063,11 @@ Updater =
         return
       Updater.lastModified = @getResponseHeader 'Last-Modified'
 
-      doc = d.implementation.createHTMLDocument ''
-      doc.documentElement.innerHTML = @response
+      if $.engine is 'presto'
+        doc = d.implementation.createHTMLDocument ''
+        doc.documentElement.innerHTML = @response
+      else
+        doc = @response
 
       lastPost = Updater.thread.lastElementChild
       id = lastPost.id[2..]
@@ -2093,15 +2101,16 @@ Updater =
 
   retry: ->
     @count.textContent = 'Retry'
-    @count.className = null
+    @count.className   = null
     @update()
 
   update: ->
     Updater.timer.textContent = 0
     Updater.request?.abort()
-    #fool the cache
+    # Fool the cache.
     url = location.pathname + '?' + Date.now()
     Updater.request = $.ajax url, onload: Updater.cb.update,
+      responseType: 'document'
       headers: 'If-Modified-Since': Updater.lastModified
 
 Watcher =