diff --git a/db/migrate/20180904115948_add_index_for_lti_parameters_external_user_id.rb b/db/migrate/20180904115948_add_index_for_lti_parameters_external_user_id.rb
new file mode 100644
index 00000000..5d0ecd46
--- /dev/null
+++ b/db/migrate/20180904115948_add_index_for_lti_parameters_external_user_id.rb
@@ -0,0 +1,5 @@
+class AddIndexForLtiParametersExternalUserId < ActiveRecord::Migration
+  def change
+    add_index :lti_parameters, :external_users_id
+  end
+end