diff --git a/src/main/kotlin/org/phoenixframework/Transport.kt b/src/main/kotlin/org/phoenixframework/Transport.kt
index 25c8818..decf354 100644
--- a/src/main/kotlin/org/phoenixframework/Transport.kt
+++ b/src/main/kotlin/org/phoenixframework/Transport.kt
@@ -155,6 +155,7 @@ class WebSocketTransport(
 
   override fun onClosing(webSocket: WebSocket, code: Int, reason: String) {
     this.readyState = Transport.ReadyState.CLOSING
+    webSocket.close(code, reason)
   }
 
   override fun onMessage(webSocket: WebSocket, text: String) {
@@ -165,4 +166,4 @@ class WebSocketTransport(
     this.readyState = Transport.ReadyState.CLOSED
     this.onClose?.invoke(code)
   }
-}
\ No newline at end of file
+}