diff --git a/fastapi/openapi/utils.py b/fastapi/openapi/utils.py
index 07791fca47..a1f00e0433 100644
--- a/fastapi/openapi/utils.py
+++ b/fastapi/openapi/utils.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import copy
 import http.client
 import inspect