diff --git a/rest_framework/serializers.py b/rest_framework/serializers.py
index 37b68cf58..be925d35f 100644
--- a/rest_framework/serializers.py
+++ b/rest_framework/serializers.py
@@ -1137,7 +1137,7 @@ class ModelSerializer(Serializer):
             "and is now disallowed. Add an explicit fields = '__all__' to the "
             "{serializer_class} serializer.".format(
                 serializer_class=self.__class__.__name__
-            ),
+            )
         )
 
         if fields == ALL_FIELDS: