diff --git a/boards/static/js/thread_update.js b/boards/static/js/thread_update.js
--- a/boards/static/js/thread_update.js
+++ b/boards/static/js/thread_update.js
@@ -28,7 +28,10 @@ var CLASS_POST = '.post'
 var POST_ADDED = 0;
 var POST_UPDATED = 1;
 
+// TODO These need to be syncronized with board settings.
 var JS_AUTOUPDATE_PERIOD = 20000;
+// TODO This needs to be the same for attachment download time limit.
+var POST_AJAX_TIMEOUT = 30000;
 
 var ALLOWED_FOR_PARTIAL_UPDATE = [
     'refmap',
@@ -446,7 +449,8 @@ function updateNodeAttr(oldNode, newNode
                 error: function() {
                     showAsErrors($('#form'), gettext('Server error!'));
                 },
-                url: '/api/add_post/' + threadId + '/'
+                url: '/api/add_post/' + threadId + '/',
+                timeout: POST_AJAX_TIMEOUT
             };
 
             form.ajaxForm(options);