diff --git a/app/controllers/concerns/lti.rb b/app/controllers/concerns/lti.rb
index 4af95e33..ea1443c6 100644
--- a/app/controllers/concerns/lti.rb
+++ b/app/controllers/concerns/lti.rb
@@ -129,7 +129,7 @@ module Lti
   private :send_scores
 
   def send_score_for(submission, user)
-    if user.consumer
+    if user.external_user? && user.consumer
       lti_parameter = user.lti_parameters.find_by(exercise: submission.exercise, study_group: submission.study_group)
       provider = build_tool_provider(consumer: user.consumer, parameters: lti_parameter&.lti_parameters)
     end