diff --git a/slow/slow.py b/slow/slow.py
index ba32f95..cc7e11f 100644
--- a/slow/slow.py
+++ b/slow/slow.py
@@ -11,8 +11,8 @@ PR = re.compile(r"\<([a-zA-Z_][a-zA-Z0-9_]*)\>")
 
 
 class CORS:
-    Origins: list[str]
-    Methods: list[str]
+    Origins: set[str]
+    Methods: set[str]
     Disabled: bool
 
     def __init__(self):