diff --git a/boot/arm-trusted-firmware/arm-trusted-firmware.mk b/boot/arm-trusted-firmware/arm-trusted-firmware.mk
index 648f62ed85..049beed36a 100644
--- a/boot/arm-trusted-firmware/arm-trusted-firmware.mk
+++ b/boot/arm-trusted-firmware/arm-trusted-firmware.mk
@@ -60,6 +60,7 @@ endif
 
 ARM_TRUSTED_FIRMWARE_MAKE_OPTS += \
 	CROSS_COMPILE="$(TARGET_CROSS)" \
+	BUILD_STRING=$(ARM_TRUSTED_FIRMWARE_VERSION) \
 	$(call qstrip,$(BR2_TARGET_ARM_TRUSTED_FIRMWARE_ADDITIONAL_VARIABLES)) \
 	PLAT=$(ARM_TRUSTED_FIRMWARE_PLATFORM) \
 	TARGET_BOARD=$(ARM_TRUSTED_FIRMWARE_TARGET_BOARD)