diff --git a/apps/transaction/serializers.py b/apps/transaction/serializers.py
index f211340..c7163c0 100644
--- a/apps/transaction/serializers.py
+++ b/apps/transaction/serializers.py
@@ -42,7 +42,7 @@ class TransactionListSerializer(serializers.ModelSerializer):
     
     class Meta:
         model = TransactionParticipant
-        fields = ['course', 'status', 'price', 'created_at', 'updated_at']
+        fields = ['id', 'course', 'status', 'price', 'created_at', 'updated_at']
         
     def get_course(self, obj):
         return CourseDetailSerializer(obj.course, context=self.context).data