diff --git a/app/models/submission.rb b/app/models/submission.rb
index c9fafb97..ad0767a4 100644
--- a/app/models/submission.rb
+++ b/app/models/submission.rb
@@ -67,9 +67,9 @@ class Submission < ActiveRecord::Base
 
   def unsolved_rfc
     # old query
-    # RequestForComment.unsolved.not(:stale).where(exercise_id: exercise).where.not(question: nil).order("RANDOM()").find { | rfc_element |(rfc_element.comments_count < MAX_COMMENTS_ON_RECOMMENDED_RFC) }
+    # RequestForComment.unsolved.where(exercise_id: exercise).where.not(question: nil).order("RANDOM()").find { | rfc_element |(rfc_element.comments_count < MAX_COMMENTS_ON_RECOMMENDED_RFC) }
 
     # experimental query:
-    RequestForComment.unsolved.joins('JOIN exercise_collections_exercises ece ON ece.exercise_id = request_for_comments.exercise_id').where('ece.exercise_collection_id != 3 OR user_id%10 > 3').where.not(question: nil).order("RANDOM()").find { | rfc_element |(rfc_element.comments_count < MAX_COMMENTS_ON_RECOMMENDED_RFC) }
+    RequestForComment.unsolved.joins('JOIN exercise_collections_exercises ece ON ece.exercise_id = request_for_comments.exercise_id').where('ece.exercise_collection_id != 3 OR user_id%10 > 3').where(exercise_id: exercise).where.not(question: nil).order("RANDOM()").find { | rfc_element |(rfc_element.comments_count < MAX_COMMENTS_ON_RECOMMENDED_RFC) }
   end
 end