diff --git a/app/models/forum_topic_visit.rb b/app/models/forum_topic_visit.rb
index 4df979466..3745c98d7 100644
--- a/app/models/forum_topic_visit.rb
+++ b/app/models/forum_topic_visit.rb
@@ -4,6 +4,6 @@ class ForumTopicVisit < ActiveRecord::Base
   attr_accessible :user_id, :user, :forum_topic_id, :forum_topic, :last_read_at
 
   def self.prune!(user)
-    where("last_read_at < ?", user.last_forum_read_at).delete_all
+    where("user_id = ? and last_read_at < ?", user.id, user.last_forum_read_at).delete_all
   end
 end