diff --git a/Firmware/Marlin_main.cpp b/Firmware/Marlin_main.cpp
index 3bcc36b3b..0ca4fe70a 100644
--- a/Firmware/Marlin_main.cpp
+++ b/Firmware/Marlin_main.cpp
@@ -5853,8 +5853,8 @@ Sigma_Exit:
     }
 
     /*!
-    ### M79 - TODO
-    Restart the printer-host enable keepalive timer. While the timer has not expired, the printer will enable host specific features.
+    ### M79 - Start host timer <a href="https://reprap.org/wiki/G-code#M79:_Start_host_timer">M79: Start host timer</a>
+    Start the printer-host enable keep-alive timer. While the timer has not expired, the printer will enable host specific features.
     #### Usage
 
         M79 [ S ]