diff --git a/bumble/hci.py b/bumble/hci.py
index 3bf5012c..05fac206 100644
--- a/bumble/hci.py
+++ b/bumble/hci.py
@@ -28,6 +28,7 @@
 from dataclasses import field
 from typing import (
     Any,
+    ClassVar,
     Literal,
     TypeVar,
     cast,