diff --git a/src/covjson_pydantic/coverage.py b/src/covjson_pydantic/coverage.py
index b209e53..013a45a 100644
--- a/src/covjson_pydantic/coverage.py
+++ b/src/covjson_pydantic/coverage.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from typing import Annotated
 from typing import Dict
 from typing import List