diff --git a/Marlin/Configuration.h b/Marlin/Configuration.h
index c12bed8afd..dd1d8e7a8d 100644
--- a/Marlin/Configuration.h
+++ b/Marlin/Configuration.h
@@ -101,7 +101,7 @@
  * Currently Ethernet (-2) is only supported on Teensy 4.1 boards.
  * :[-2, -1, 0, 1, 2, 3, 4, 5, 6, 7]
  */
-#define SERIAL_PORT_2 1
+#define SERIAL_PORT_2 -1
 //#define BAUDRATE_2 250000   // :[2400, 9600, 19200, 38400, 57600, 115200, 250000, 500000, 1000000] Enable to override BAUDRATE
 
 /**