diff --git a/conf/machine/raspberrypi3-64.conf b/conf/machine/raspberrypi3-64.conf
index 0efe3ff..60f823b 100644
--- a/conf/machine/raspberrypi3-64.conf
+++ b/conf/machine/raspberrypi3-64.conf
@@ -33,7 +33,7 @@ KERNEL_DEVICETREE = " \
     overlays/vc4-kms-v3d.dtbo \
     "
 
-SERIAL_CONSOLE = "115200 ttyS0"
+SERIAL_CONSOLE ?= "115200 ttyS0"
 VC4_CMA_SIZE ?= "cma-256"
 
 UBOOT_MACHINE = "rpi_3_config"