diff --git a/meta-raspberrypi/conf/machine/raspberrypi-cm.conf b/meta-raspberrypi/conf/machine/raspberrypi-cm.conf
index 2da7d50..f9371df 100644
--- a/meta-raspberrypi/conf/machine/raspberrypi-cm.conf
+++ b/meta-raspberrypi/conf/machine/raspberrypi-cm.conf
@@ -4,3 +4,5 @@
 
 MACHINEOVERRIDES = "raspberrypi:${MACHINE}"
 include conf/machine/raspberrypi.conf
+
+ARMSTUB ?= "armstub.bin"