diff --git a/college/security/groups.xml b/college/security/groups.xml
index 72d5a99..77ecb3b 100644
--- a/college/security/groups.xml
+++ b/college/security/groups.xml
@@ -19,7 +19,7 @@
     <!-- 学生只能访问自己的习题作答 -->
     <record id="rule_exercise_answer_student_own" model="ir.rule">
         <field name="name">习题作答：学生仅能访问自己的回答</field>
-        <field name="model_id" search="[('model', '=', 'yuthon.school.course.chapter.exercise.answer')]"/>
+        <field name="model_id" ref="model_yuthon_school_course_chapter_exercise_answer"/>
         <field name="groups" eval="[(4, ref('college.group_student'))]"/>
         <field name="domain_force">[('user_id', '=', user.id)]</field>
         <field name="perm_read" eval="True"/>