diff --git a/README-CN.md b/README-CN.md
index 39769f0..e95ccd9 100644
--- a/README-CN.md
+++ b/README-CN.md
@@ -8,6 +8,7 @@
 
 支持 MQTT over WebSocket。
 
+> [!IMPORTANT]
 > 首个支持 MQTT `5.0` 协议的 PHP library。
 
 [![License](https://poser.pugx.org/simps/mqtt/license)](LICENSE)
diff --git a/README.md b/README.md
index 74f7b49..e7a9ff5 100644
--- a/README.md
+++ b/README.md
@@ -10,6 +10,7 @@ Support for `QoS 0`, `QoS 1`, `QoS 2`.
 
 Support for MQTT over WebSocket.
 
+> [!IMPORTANT]
 > The first PHP library to support the MQTT `5.0` protocol.
 
 [![License](https://poser.pugx.org/simps/mqtt/license)](LICENSE)