diff --git a/requirements/adapter_dev.txt b/requirements/adapter_dev.txt
index 7c479fd4b..1c3accd0d 100644
--- a/requirements/adapter_dev.txt
+++ b/requirements/adapter_dev.txt
@@ -26,7 +26,7 @@ sanic>=25.3.0,<26; python_version>"3.8"
 
 starlette>=0.19.1,<0.45; python_version<"3.9"
 starlette>=0.49.3,<1; python_version>="3.9"
-tornado>=6,<7
+tornado>=6.5.6,<7
 uvicorn<1                                # The oldest version can vary among Python runtime versions
 gunicorn>=23.0.0,<24
 websocket_client>=1.2.3,<2               # Socket Mode 3rd party implementation