diff --git a/target/linux/ar71xx/base-files/lib/upgrade/platform.sh b/target/linux/ar71xx/base-files/lib/upgrade/platform.sh
index d48135a6d3b8251aecca6ad6215bf79c9effe132..576ff6c06ccbc018a158900047b1da8d0bc2d997 100755
--- a/target/linux/ar71xx/base-files/lib/upgrade/platform.sh
+++ b/target/linux/ar71xx/base-files/lib/upgrade/platform.sh
@@ -684,6 +684,14 @@ platform_pre_upgrade() {
 	wndr4300)
 		nand_do_upgrade "$1"
 		;;
+	rb-750-r2|\
+	rb-750up-r2|\
+	rb-941-2nd|\
+	rb-951ui-2nd|\
+	rb-mapl-2nd)
+		# erase firmware if booted from initramfs
+		[ -z "$(rootfs_type)" ] && mtd erase firmware
+		;;
 	mr18|\
 	z1)
 		merakinand_do_upgrade "$1"