diff --git a/app/assets/javascripts/discourse/components/category_group_component.js b/app/assets/javascripts/discourse/components/category_group_component.js
index 40ea90878..9fae6cc23 100644
--- a/app/assets/javascripts/discourse/components/category_group_component.js
+++ b/app/assets/javascripts/discourse/components/category_group_component.js
@@ -11,7 +11,8 @@ Discourse.CategoryGroupComponent = Ember.Component.extend({
         return Discourse.Category.list().filter(function(category){
           var regex = new RegExp(term, "i");
           return category.get("name").match(regex) &&
-            !_.contains(self.get('categories'), category);
+            !_.contains(self.get('blacklist') || [], category) &&
+            !_.contains(self.get('categories'), category) ;
         });
       },
       onChangeItems: function(items) {
diff --git a/app/assets/javascripts/discourse/controllers/preferences_controller.js b/app/assets/javascripts/discourse/controllers/preferences_controller.js
index fa800b0a1..c5f6c1430 100644
--- a/app/assets/javascripts/discourse/controllers/preferences_controller.js
+++ b/app/assets/javascripts/discourse/controllers/preferences_controller.js
@@ -15,6 +15,10 @@ Discourse.PreferencesController = Discourse.ObjectController.extend({
     return Discourse.SiteSettings.allow_user_locale;
   }.property(),
 
+  selectedCategories: function(){
+    return [].concat(this.get("watchedCategories"), this.get("trackedCategories"), this.get("mutedCategories"));
+  }.property("watchedCategories", "trackedCategories", "mutedCategories"),
+
   // By default we haven't saved anything
   saved: false,
 
diff --git a/app/assets/javascripts/discourse/templates/user/preferences.js.handlebars b/app/assets/javascripts/discourse/templates/user/preferences.js.handlebars
index d87c2f7c9..be9d804b6 100644
--- a/app/assets/javascripts/discourse/templates/user/preferences.js.handlebars
+++ b/app/assets/javascripts/discourse/templates/user/preferences.js.handlebars
@@ -187,17 +187,17 @@
       <label class="control-label">{{i18n user.categories_settings}}</label>
       <div class="controls category-controls">
         <label>{{i18n user.watched_categories}}</label>
-        {{category-group categories=watchedCategories}}
+        {{category-group categories=watchedCategories blacklist=selectedCategories}}
       </div>
       <div class="instructions">{{i18n user.watched_categories_instructions}}</div>
       <div class="controls category-controls">
         <label>{{i18n user.tracked_categories}}</label>
-        {{category-group categories=trackedCategories}}
+        {{category-group categories=trackedCategories blacklist=selectedCategories}}
       </div>
       <div class="instructions">{{i18n user.tracked_categories_instructions}}</div>
       <div class="controls category-controls">
         <label>{{i18n user.muted_categories}}</label>
-        {{category-group categories=mutedCategories}}
+        {{category-group categories=mutedCategories blacklist=selectedCategories}}
       </div>
       <div class="instructions">{{i18n user.muted_categories_instructions}}</div>
     </div>