diff --git a/pyproject.toml b/pyproject.toml
index ed08cff..83358ca 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -28,7 +28,7 @@ keywords = []
 dependencies = [
     "requests==2.32.4", 
     "openfeature-sdk==0.4.2", 
-    "typing_extensions==4.9.0",
+    "typing_extensions>=4.9.0,<5.0.0",
     "httpx==0.27.2",
     "protobuf==5.29.5"
 ]