diff --git a/docs/api-guide/serializers.md b/docs/api-guide/serializers.md
index 4d032bd9e..da57ac0a4 100644
--- a/docs/api-guide/serializers.md
+++ b/docs/api-guide/serializers.md
@@ -524,6 +524,7 @@ You can add extra fields to a `ModelSerializer` or override the default fields b
 
         class Meta:
             model = Account
+            fields = ['url', 'groups']
 
 Extra fields can correspond to any property or callable on the model.