diff --git a/friends/serializers.py b/friends/serializers.py
index fe03628..b4ce31f 100644
--- a/friends/serializers.py
+++ b/friends/serializers.py
@@ -131,7 +131,7 @@ class Meta:
         ]
 
     def get_rating_average(self, obj):
-        return obj.rating_average()
+        return str(obj.rating_average())
 
     def get_image_url(self, obj):
         if obj.image_url:  # image_url이 null이 아닌 경우에만 처리