diff --git a/src/Filtering/ThreadHiding.coffee b/src/Filtering/ThreadHiding.coffee
index e0ed48f41..2729945fa 100755
--- a/src/Filtering/ThreadHiding.coffee
+++ b/src/Filtering/ThreadHiding.coffee
@@ -1,13 +1,36 @@
 ThreadHiding =
   init: ->
-    return if g.VIEW isnt 'index' or !Conf['Thread Hiding Buttons'] and !Conf['Thread Hiding Link']
-
+    return if g.VIEW is 'thread' or !Conf['Thread Hiding Buttons'] and !Conf['Thread Hiding Link']
     @db = new DataBoard 'hiddenThreads'
-    @syncCatalog()
+    return @catalogHide() if g.VIEW is 'catalog'
     Thread.callbacks.push
       name: 'Thread Hiding'
       cb:   @node
 
+  catalogHide: ->
+    @hiddenThreads = ThreadHiding.db.get
+      boardID: g.BOARD.ID
+      defaultValue: {}
+    @hiddenThreads[threadID] = true for threadID of @hiddenThreads
+    localStorage.setItem "4chan-hide-t-#{g.BOARD}", JSON.stringify @hiddenThreads
+    $.ready ->
+      new MutationObserver(ThreadHiding.catalogSave).observe $.id('threads'),
+        attributes: true
+        subtree: true
+        attributeFilter: ['style']
+
+  catalogSave: ->
+    hiddenThreads2 = JSON.parse localStorage.getItem "4chan-hide-t-#{g.BOARD}"
+    for threadID of hiddenThreads2 when !(threadID of ThreadHiding.hiddenThreads)
+      ThreadHiding.db.set
+        boardID:  g.BOARD.ID
+        threadID: threadID
+        val:      {makeStub: Conf['Stubs']}
+    for threadID of ThreadHiding.hiddenThreads when !(threadID of hiddenThreads2)
+      ThreadHiding.db.delete
+        boardID:  g.BOARD.ID
+        threadID: threadID
+
   node: ->
     if data = ThreadHiding.db.get {boardID: @board.ID, threadID: @ID}
       ThreadHiding.hide @, data.makeStub
@@ -21,47 +44,6 @@ ThreadHiding =
         ThreadHiding.makeStub thread, root
     return
 
-  syncCatalog: ->
-    # Sync hidden threads from the catalog into the index.
-    hiddenThreads = ThreadHiding.db.get
-      boardID: g.BOARD.ID
-      defaultValue: {}
-    hiddenThreadsOnCatalog = JSON.parse(localStorage.getItem "4chan-hide-t-#{g.BOARD}") or {}
-
-    # Add threads that were hidden in the catalog.
-    for threadID of hiddenThreadsOnCatalog
-      unless threadID of hiddenThreads
-        hiddenThreads[threadID] = {}
-
-    # Remove threads that were un-hidden in the catalog.
-    for threadID of hiddenThreads
-      unless threadID of hiddenThreadsOnCatalog
-        delete hiddenThreads[threadID]
-
-    if (ThreadHiding.db.data.lastChecked or 0) > Date.now() - $.MINUTE
-      # Was cleaned just now.
-      ThreadHiding.cleanCatalog hiddenThreadsOnCatalog
-
-    ThreadHiding.db.set
-      boardID: g.BOARD.ID
-      val: hiddenThreads
-
-  cleanCatalog: (hiddenThreadsOnCatalog) ->
-    # We need to clean hidden threads on the catalog ourselves,
-    # otherwise if we don't visit the catalog regularly
-    # it will pollute the localStorage and our data.
-    $.cache "//a.4cdn.org/#{g.BOARD}/threads.json", ->
-      return unless @status is 200
-      threads = {}
-      for page in @response
-        for thread in page.threads
-          if thread.no of hiddenThreadsOnCatalog
-            threads[thread.no] = hiddenThreadsOnCatalog[thread.no]
-      if Object.keys(threads).length
-        localStorage.setItem "4chan-hide-t-#{g.BOARD}", JSON.stringify threads
-      else
-        localStorage.removeItem "4chan-hide-t-#{g.BOARD}"
-
   menu:
     init: ->
       return if g.VIEW isnt 'index' or !Conf['Menu'] or !Conf['Thread Hiding Link']
@@ -161,19 +143,15 @@ ThreadHiding =
     $.prepend root, thread.stub
 
   saveHiddenState: (thread, makeStub) ->
-    hiddenThreadsOnCatalog = JSON.parse(localStorage.getItem "4chan-hide-t-#{g.BOARD}") or {}
     if thread.isHidden
       ThreadHiding.db.set
         boardID:  thread.board.ID
         threadID: thread.ID
         val: {makeStub}
-      hiddenThreadsOnCatalog[thread] = true
     else
       ThreadHiding.db.delete
         boardID:  thread.board.ID
         threadID: thread.ID
-      delete hiddenThreadsOnCatalog[thread]
-    localStorage.setItem "4chan-hide-t-#{g.BOARD}", JSON.stringify hiddenThreadsOnCatalog
 
   toggle: (thread) ->
     unless thread instanceof Thread
diff --git a/src/General/Settings.coffee b/src/General/Settings.coffee
index 88e13eb63..f7a0d4122 100755
--- a/src/General/Settings.coffee
+++ b/src/General/Settings.coffee
@@ -123,10 +123,7 @@ Settings =
       button.textContent = "Hidden: #{hiddenNum}"
     $.on button, 'click', ->
       @textContent = 'Hidden: 0'
-      $.get 'hiddenThreads', {}, ({hiddenThreads}) ->
-        for boardID of hiddenThreads.boards
-          localStorage.removeItem "4chan-hide-t-#{boardID}"
-        $.delete ['hiddenThreads', 'hiddenPosts']
+      $.delete ['hiddenThreads', 'hiddenPosts']
     $.after $('input[name="Stubs"]', section).parentNode.parentNode, div
   export: ->
     # Make sure to export the most recent data.