From f11c6d5d02a3992e95c6450a8b7a062aab28f180 Mon Sep 17 00:00:00 2001
From: Marcio Teixeira <marcio@alephobjects.com>
Date: Tue, 15 Jan 2019 17:45:18 -0700
Subject: [PATCH] Fix M107 when dual-nozzles share fan (#12819) (#12909)

---
 Marlin/src/gcode/temperature/M106_M107.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Marlin/src/gcode/temperature/M106_M107.cpp b/Marlin/src/gcode/temperature/M106_M107.cpp
index 8b9daa779c..7150f7db3b 100644
--- a/Marlin/src/gcode/temperature/M106_M107.cpp
+++ b/Marlin/src/gcode/temperature/M106_M107.cpp
@@ -63,7 +63,8 @@ void GcodeSuite::M106() {
  * M107: Fan Off
  */
 void GcodeSuite::M107() {
-  thermalManager.set_fan_speed(parser.byteval('P', active_extruder), 0);
+  const uint8_t p = parser.byteval('P', MIN(active_extruder, FAN_COUNT - 1));
+  thermalManager.set_fan_speed(p, 0);
 }
 
 #endif // FAN_COUNT > 0