diff --git a/src/marshmallow/schema.py b/src/marshmallow/schema.py
index 2eae21546..6f15a0f3c 100644
--- a/src/marshmallow/schema.py
+++ b/src/marshmallow/schema.py
@@ -117,6 +117,7 @@ def __new__(mcs, name, bases, attrs):
             klass=klass,
             cls_fields=cls_fields,
             inherited_fields=inherited_fields,
+            dict_cls=dict,
         )
         return klass