diff --git a/slow/slow.py b/slow/slow.py
index cc7e11f..0e2fa25 100644
--- a/slow/slow.py
+++ b/slow/slow.py
@@ -17,8 +17,8 @@ class CORS:
 
     def __init__(self):
         self.Disabled = False
-        self.Origins = []
-        self.Methods = ["GET", "POST", "PUT", "DELETE", "PATCH", "HEAD"]
+        self.Origins: set[str] = {}
+        self.Methods: set[str] = {"GET", "POST", "PUT", "DELETE", "PATCH", "HEAD"}
 
 
 class Headers: