diff --git a/stdlib/keyword.pyi b/stdlib/keyword.pyi
index c17c58012fd1..46c386048858 100644
--- a/stdlib/keyword.pyi
+++ b/stdlib/keyword.pyi
@@ -1,5 +1,6 @@
 import sys
 from collections.abc import Sequence
+from typing_extensions import Final
 
 if sys.version_info >= (3, 9):
     __all__ = ["iskeyword", "issoftkeyword", "kwlist", "softkwlist"]
@@ -8,8 +9,13 @@ else:
 
 def iskeyword(s: str) -> bool: ...
 
-kwlist: Sequence[str]
+# a list at runtime, but you're not meant to mutate it;
+# type it as a sequence
+kwlist: Final[Sequence[str]]
 
 if sys.version_info >= (3, 9):
     def issoftkeyword(s: str) -> bool: ...
-    softkwlist: Sequence[str]
+
+    # a list at runtime, but you're not meant to mutate it;
+    # type it as a sequence
+    softkwlist: Final[Sequence[str]]