diff --git a/jam/__init__.py b/jam/__init__.py
index d8b7887..aad6795 100644
--- a/jam/__init__.py
+++ b/jam/__init__.py
@@ -3,7 +3,7 @@
 from dataclasses import dataclass
 
 from marshmallow import fields, post_load
-from marshmallow.schema import SchemaMeta as BaseSchemaMeta, BaseSchema, with_metaclass
+from marshmallow.schema import SchemaMeta as BaseSchemaMeta, BaseSchema
 
 import datetime as dt
 import uuid
@@ -119,7 +119,7 @@ def __new__(mcs, name, bases, attrs):
         return new_class
 
 
-class Schema(with_metaclass(SchemaMeta, BaseSchema)):
+class Schema(BaseSchema, metaclass=SchemaMeta):
     __doc__ = BaseSchema.__doc__
 
     @post_load
diff --git a/project.ini b/project.ini
index a6f6e2b..0ce3426 100644
--- a/project.ini
+++ b/project.ini
@@ -1,5 +1,5 @@
 [project]
 url = https://github.com/nonamenix/marshmallow-jam
-version = 1.1.2
+version = 1.2.0
 name = marshmallow-jam
 description = Some extra sweets for marshmallow.
\ No newline at end of file
diff --git a/requirements.txt b/requirements.txt
index b307ae6..fa7b218 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1 +1 @@
-marshmallow<=3.0.0rc5<=3.0.0rc4
+marshmallow>=3.0.0rc6