diff --git a/app/services/copy_ec_year_service.rb b/app/services/copy_ec_year_service.rb
index 83073d53..7ad46c5f 100644
--- a/app/services/copy_ec_year_service.rb
+++ b/app/services/copy_ec_year_service.rb
@@ -197,7 +197,7 @@
    def copy_graduation_subitem_course_targets!(target, to_target)
      target.ec_graduation_subitem_course_targets.each do |support|
        to_support = to_target.ec_graduation_subitem_course_targets.new
-       to_support.attributes = support.attributes.except('id', 'ec_graduation_subitem_id', 'created_at', 'updated_at')
+       to_support.attributes = support.attributes.except('id', 'ec_course_target_id', 'ec_graduation_subitem_id', 'created_at', 'updated_at')
        to_support.ec_graduation_subitem_id = graduation_subitem_map[support.ec_graduation_subitem_id]
        to_support.save!
      end