diff --git a/wideq/client.py b/wideq/client.py
index f6a1ae8..32229e0 100644
--- a/wideq/client.py
+++ b/wideq/client.py
@@ -11,8 +11,6 @@ from typing import Any, Dict, Generator, List, Optional
 
 from . import core
 
-DEFAULT_COUNTRY = 'US'
-DEFAULT_LANGUAGE = 'en-US'
 #: Represents an unknown enum value.
 _UNKNOWN = 'Unknown'
 
@@ -79,8 +77,8 @@ class Client(object):
                  gateway: Optional[core.Gateway] = None,
                  auth: Optional[core.Auth] = None,
                  session: Optional[core.Session] = None,
-                 country: str = DEFAULT_COUNTRY,
-                 language: str = DEFAULT_LANGUAGE) -> None:
+                 country: str = core.DEFAULT_COUNTRY,
+                 language: str = core.DEFAULT_LANGUAGE) -> None:
         # The three steps required to get access to call the API.
         self._gateway: Optional[core.Gateway] = gateway
         self._auth: Optional[core.Auth] = auth
@@ -146,12 +144,7 @@ class Client(object):
         client = cls()
 
         if 'gateway' in state:
-            data = state['gateway']
-            client._gateway = core.Gateway(
-                data['auth_base'], data['api_root'], data['oauth_root'],
-                data.get('country', DEFAULT_COUNTRY),
-                data.get('language', DEFAULT_LANGUAGE),
-            )
+            client._gateway = core.Gateway.deserialize(state['gateway'])
 
         if 'auth' in state:
             data = state['auth']
@@ -181,19 +174,10 @@ class Client(object):
         }
 
         if self._gateway:
-            out['gateway'] = {
-                'auth_base': self._gateway.auth_base,
-                'api_root': self._gateway.api_root,
-                'oauth_root': self._gateway.oauth_root,
-                'country': self._gateway.country,
-                'language': self._gateway.language,
-            }
+            out['gateway'] = self._gateway.serialize()
 
         if self._auth:
-            out['auth'] = {
-                'access_token': self._auth.access_token,
-                'refresh_token': self._auth.refresh_token,
-            }
+            out['auth'] = self._auth.serialize()
 
         if self._session:
             out['session'] = self._session.session_id
@@ -218,8 +202,8 @@ class Client(object):
         """
 
         client = cls(
-            country=country or DEFAULT_COUNTRY,
-            language=language or DEFAULT_LANGUAGE,
+            country=country or core.DEFAULT_COUNTRY,
+            language=language or core.DEFAULT_LANGUAGE,
         )
         client._auth = core.Auth(client.gateway, None, refresh_token)
         client.refresh()
diff --git a/wideq/core.py b/wideq/core.py
index be976a8..7b2a806 100644
--- a/wideq/core.py
+++ b/wideq/core.py
@@ -18,6 +18,8 @@ CLIENT_ID = 'LGAO221A02'
 OAUTH_SECRET_KEY = 'c053c2a6ddeb7ad97cb0eed0dcb31cf8'
 OAUTH_CLIENT_KEY = 'LGAO221A02'
 DATE_FORMAT = '%a, %d %b %Y %H:%M:%S +0000'
+DEFAULT_COUNTRY = 'US'
+DEFAULT_LANGUAGE = 'en-US'
 
 
 def gen_uuid() -> str:
@@ -253,6 +255,21 @@ class Gateway(object):
     def oauth_url(self):
         return oauth_url(self.auth_base, self.country, self.language)
 
+    def serialize(self) -> Dict[str, str]:
+        return {
+            'auth_base': self.auth_base,
+            'api_root': self.api_root,
+            'oauth_root': self.oauth_root,
+            'country': self.country,
+            'language': self.language,
+        }
+
+    @classmethod
+    def deserialize(cls, data: Dict[str, Any]) -> 'Gateway':
+        return cls(data['auth_base'], data['api_root'], data['oauth_root'],
+                   data.get('country', DEFAULT_COUNTRY),
+                   data.get('language', DEFAULT_LANGUAGE))
+
 
 class Auth(object):
     def __init__(self, gateway, access_token, refresh_token):
@@ -286,6 +303,12 @@ class Auth(object):
                                         self.refresh_token)
         return Auth(self.gateway, new_access_token, self.refresh_token)
 
+    def serialize(self) -> Dict[str, str]:
+        return {
+            'access_token': self.access_token,
+            'refresh_token': self.refresh_token,
+        }
+
 
 class Session(object):
     def __init__(self, auth, session_id) -> None: