diff --git a/users/serializers.py b/users/serializers.py
index 315224f..9110442 100644
--- a/users/serializers.py
+++ b/users/serializers.py
@@ -30,6 +30,15 @@ class SetPortofolioRequiredInfoSerializer(serializers.ModelSerializer):
         model = User
         fields = ['custom_url', 'job_and_interests']
 
+    def validate(self, attrs):
+        custom_url = attrs.get("custom_url")
+
+        if custom_url and (" " in custom_url or "." in custom_url):
+            raise serializers.ValidationError({
+                "message": "하지말라면 하지 좀 마"
+            })
+        
+        return super().validate(attrs)
 class TagUserSerializer(serializers.ModelSerializer):
     class Meta:
         model = User