From 9dc2712c47f9ce6e5eb0c388a3d50a3a28574c27 Mon Sep 17 00:00:00 2001
From: X-Ryl669 <boite.pour.spam@gmail.com>
Date: Fri, 12 Mar 2021 12:25:30 +0100
Subject: [PATCH] Undef unused 2nd serial option(s) (#21331)

Co-authored-by: Scott Lahteine <github@thinkyhead.com>
---
 Marlin/src/inc/Conditionals_post.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Marlin/src/inc/Conditionals_post.h b/Marlin/src/inc/Conditionals_post.h
index 7dc75db1c2..a6567e9714 100644
--- a/Marlin/src/inc/Conditionals_post.h
+++ b/Marlin/src/inc/Conditionals_post.h
@@ -2913,6 +2913,9 @@
   #define HAS_MULTI_SERIAL 1
 #endif
 
-#if ENABLED(MEATPACK_ON_SERIAL_PORT_1) || BOTH(HAS_MULTI_SERIAL, MEATPACK_ON_SERIAL_PORT_2)
+#if !HAS_MULTI_SERIAL
+  #undef MEATPACK_ON_SERIAL_PORT_2
+#endif
+#if EITHER(MEATPACK_ON_SERIAL_PORT_1, MEATPACK_ON_SERIAL_PORT_2)
   #define HAS_MEATPACK 1
 #endif