diff --git a/app/controllers/concerns/submission_scoring.rb b/app/controllers/concerns/submission_scoring.rb
index 6c258a5a..9bf9cda3 100644
--- a/app/controllers/concerns/submission_scoring.rb
+++ b/app/controllers/concerns/submission_scoring.rb
@@ -88,7 +88,7 @@ module SubmissionScoring
     # Return all test results except for those of a linter if not allowed
     show_linter = Python20CourseWeek.show_linter? submission.exercise, submission.user_id
     outputs&.reject do |output|
-      next if show_linter
+      next if show_linter || output.blank?
 
       output[:file_role] == 'teacher_defined_linter'
     end