diff --git a/apps/qm/serializers.py b/apps/qm/serializers.py
index e5639e2c..ffa7cc1e 100644
--- a/apps/qm/serializers.py
+++ b/apps/qm/serializers.py
@@ -339,7 +339,7 @@ class FtestSerializer(CustomModelSerializer):
 class PtestSerializer(CustomModelSerializer):
     testitem_name = serializers.CharField(
         source='testitem.name', read_only=True)
-    test_user_name = serializers.CharField(source='test_user', read_only=True)
+    test_user_name = serializers.CharField(source='test_user.name', read_only=True)
 
     class Meta:
         model = Ptest