diff --git a/sys/arm/conf/GENERIC b/sys/arm/conf/GENERIC
index 474198ebaf6b..ef7630efc379 100644
--- a/sys/arm/conf/GENERIC
+++ b/sys/arm/conf/GENERIC
@@ -277,4 +277,11 @@ device		aw_thermal	# Allwinner Thermal Sensor Controller
 
 # Flattened Device Tree
 options 	FDT			# Configure using FDT/DTB data
-makeoptions	MODULES_EXTRA="dtb/allwinner dtb/am335x dtb/imx6 dtb/nvidia dtb/rpi dtb/zynq dtb/omap4"
+makeoptions	MODULES_EXTRA+="dtb/allwinner"
+makeoptions	MODULES_EXTRA+="dtb/am335x"
+makeoptions	MODULES_EXTRA+="dtb/imx6"
+makeoptions	MODULES_EXTRA+="dtb/nvidia"
+makeoptions	MODULES_EXTRA+="dtb/omap4"
+makeoptions	MODULES_EXTRA+="dtb/rpi"
+makeoptions	MODULES_EXTRA+="dtb/zynq"
+