diff --git a/README.md b/README.md
index 9e03808..4725e4e 100644
--- a/README.md
+++ b/README.md
@@ -23,7 +23,7 @@ docs](https://docs.espressif.com/projects/esp-idf/en/release-v5.0/esp32/index.ht
 
 ## TCP Control Protocol
 
-Simple, binary, command / reponse protocol.
+Simple, binary, command / reponse protocol. Port number 3498.
 
 Capabilities:
 - Get firmware version