diff --git a/Firmware/Marlin_main.cpp b/Firmware/Marlin_main.cpp
index 6c8c423c..ed855fdc 100755
--- a/Firmware/Marlin_main.cpp
+++ b/Firmware/Marlin_main.cpp
@@ -3964,6 +3964,7 @@ static void extended_capabilities_report()
     // AUTOREPORT_POSITION (M114)
     cap_line(PSTR("AUTOREPORT_POSITION"), ENABLED(AUTO_REPORT));
     //@todo Update RepRap cap
+    cap_line(PSTR("EXTENDED_M20"), 1);
 }
 #endif //EXTENDED_CAPABILITIES_REPORT