diff --git a/app/models/group.rb b/app/models/group.rb
index 498733cc1..fb43e0e18 100644
--- a/app/models/group.rb
+++ b/app/models/group.rb
@@ -38,7 +38,7 @@ class Group < ActiveRecord::Base
 
   def posts_for(guardian, before_post_id=nil)
     user_ids = group_users.map {|gu| gu.user_id}
-    result = Post.where(user_id: user_ids).includes(:user, :topic).references(:posts, :topics)
+    result = Post.where(user_id: user_ids).includes(:user, :topic, :topic => :category).references(:posts, :topics, :category)
                  .where('topics.archetype <> ?', Archetype.private_message)
                  .where(post_type: Post.types[:regular])