diff --git a/discord/permissions.py b/discord/permissions.py
index 9ba0e3f04..0f4080b21 100644
--- a/discord/permissions.py
+++ b/discord/permissions.py
@@ -529,6 +529,8 @@ class PermissionOverwrite:
         Set the value of permissions by their name.
     """
 
+    __slots__ = ('_values',)
+
     def __init__(self, **kwargs):
         self._values = {}