diff --git a/lib/topic_view.rb b/lib/topic_view.rb
index d582b4a5e2d..1ad15dc8798 100644
--- a/lib/topic_view.rb
+++ b/lib/topic_view.rb
@@ -377,7 +377,7 @@ class TopicView
     @unfiltered_post_ids ||=
       begin
         if @contains_gaps
-          unfiltered_post.pluck(:id)
+          unfiltered_posts.pluck(:id)
         else
           filtered_post_ids
         end