diff --git a/documentation/jetty-documentation/src/main/asciidoc/programming-guide/websocket.adoc b/documentation/jetty-documentation/src/main/asciidoc/programming-guide/websocket.adoc
index 42171af4e039..2ec08808b530 100644
--- a/documentation/jetty-documentation/src/main/asciidoc/programming-guide/websocket.adoc
+++ b/documentation/jetty-documentation/src/main/asciidoc/programming-guide/websocket.adoc
@@ -46,6 +46,8 @@ This event is emitted when the WebSocket communication encounters a fatal error,
 Applications interested in the error event receive a `Throwable` that represent the error.
 * The _message_ event.
 The message event is emitted when a WebSocket message is received.
+Only one thread at a time will be delivering a message event to the `onMessage` method; the next message event will not be delivered until the previous call to the `onMessage` method has exited.
+Endpoints will always be notified of message events in the same order they were received over the network.
 The message event can be of two types:
 ** Textual message event.
 Applications interested in this type of messages receive a `String` representing the UTF-8 bytes received.