diff --git a/app/policies/study_group_policy.rb b/app/policies/study_group_policy.rb
index 3dd29aeb..f19af1f1 100644
--- a/app/policies/study_group_policy.rb
+++ b/app/policies/study_group_policy.rb
@@ -4,7 +4,7 @@ class StudyGroupPolicy < AdminOnlyPolicy
   end
 
   [:show?, :destroy?, :edit?, :update?, :stream_la?].each do |action|
-    define_method(action) { admin? || @user.teacher? && @record.present? && @record.users.include?(@user) }
+    define_method(action) { admin? || @user.teacher? && @record.present? && @user.study_groups.exists?(@record.id) }
   end
 
   class Scope < Scope