diff --git a/Marlin/Configuration.h b/Marlin/Configuration.h
index 46d6b96dd..7f228b55c 100644
--- a/Marlin/Configuration.h
+++ b/Marlin/Configuration.h
@@ -72,6 +72,7 @@
 // 301= Rambo
 // 21 = Elefu Ra Board (v3)
 // 88 = 5DPrint D8 Driver Board
+// 999 = Leapfrog
 
 #ifndef MOTHERBOARD
 #define MOTHERBOARD 7