diff --git a/4chan_x.user.js b/4chan_x.user.js
index 8b6a95641..dd3e4d5d0 100644
--- a/4chan_x.user.js
+++ b/4chan_x.user.js
@@ -379,10 +379,10 @@
       return el.hidden = false;
     },
     addClass: function(el, className) {
-      return el.className += ' ' + className;
+      return el.classList.add(className);
     },
     removeClass: function(el, className) {
-      return el.className = el.className.replace(' ' + className, '');
+      return el.classList.remove(className);
     },
     rm: function(el) {
       return el.parentNode.removeChild(el);
@@ -1618,7 +1618,7 @@
       }
     },
     toggle: function(thread) {
-      if (thread.className.indexOf('stub') !== -1 || thread.hidden) {
+      if (thread.classList.contains('stub') || thread.hidden) {
         return threadHiding.show(thread);
       } else {
         return threadHiding.hide(thread);
diff --git a/script.coffee b/script.coffee
index 8a01d658f..40804e679 100644
--- a/script.coffee
+++ b/script.coffee
@@ -258,9 +258,9 @@ $.extend $,
   show: (el) ->
     el.hidden = false
   addClass: (el, className) ->
-    el.className += ' ' + className
+    el.classList.add className
   removeClass: (el, className) ->
-    el.className = el.className.replace ' ' + className, ''
+    el.classList.remove className
   rm: (el) ->
     el.parentNode.removeChild el
   append: (parent, children...) ->
@@ -1311,7 +1311,7 @@ threadHiding =
       threadHiding.show thread
 
   toggle: (thread) ->
-    if thread.className.indexOf('stub') != -1 or thread.hidden
+    if thread.classList.contains('stub') or thread.hidden
       threadHiding.show thread
     else
       threadHiding.hide thread