diff --git a/app/models/category.rb b/app/models/category.rb
index 309ae4282..390f8f2d3 100644
--- a/app/models/category.rb
+++ b/app/models/category.rb
@@ -133,7 +133,8 @@ SQL
     # If you refactor this, test performance on a large database.
 
     Category.all.each do |c|
-      topics = c.topics.where(['topics.id <> ?', c.topic_id]).visible
+      topics = c.topics.visible
+      topics = topics.where(['topics.id <> ?', c.topic_id]) if c.topic_id
       c.topics_year  = topics.created_since(1.year.ago).count
       c.topics_month = topics.created_since(1.month.ago).count
       c.topics_week  = topics.created_since(1.week.ago).count
diff --git a/spec/models/category_spec.rb b/spec/models/category_spec.rb
index a71d78f4f..700d5e32a 100644
--- a/spec/models/category_spec.rb
+++ b/spec/models/category_spec.rb
@@ -380,6 +380,26 @@ describe Category do
         @category.posts_week.should == 1
       end
     end
+
+    context 'for uncategorized category' do
+      before do
+        @uncategorized = Category.find(SiteSetting.uncategorized_category_id)
+        create_post(user: Fabricate(:user), category: @uncategorized.name)
+        Category.update_stats
+        @uncategorized.reload
+      end
+
+      it 'updates topic stats' do
+        @uncategorized.topics_week.should == 1
+        @uncategorized.topics_month.should == 1
+        @uncategorized.topics_year.should == 1
+        @uncategorized.topic_count.should == 1
+        @uncategorized.post_count.should == 1
+        @uncategorized.posts_year.should == 1
+        @uncategorized.posts_month.should == 1
+        @uncategorized.posts_week.should == 1
+      end
+    end
   end
 
   describe "#url" do