--- Makefile.orig	2021-02-05 20:37:42.864127028 +0000
+++ Makefile	2021-02-05 20:38:16.902167034 +0000
@@ -98,7 +98,7 @@
 	ARCH_SUFFIX_UPPER	?= AA64
 	FORMAT			:= -O binary
 	SUBSYSTEM		:= 0xa
-	ARCH_LDFLAGS		+= --defsym=EFI_SUBSYSTEM=$(SUBSYSTEM)
+	override ARCH_LDFLAGS	+= --defsym=EFI_SUBSYSTEM=$(SUBSYSTEM)
 endif
 ifeq ($(ARCH),arm)
 	CFLAGS += -DMDE_CPU_ARM -DPAGE_SIZE=4096 -mstrict-align
@@ -107,7 +107,7 @@
 	ARCH_SUFFIX_UPPER	?= ARM
 	FORMAT			:= -O binary
 	SUBSYSTEM		:= 0xa
-	ARCH_LDFLAGS		+= --defsym=EFI_SUBSYSTEM=$(SUBSYSTEM)
+	override ARCH_LDFLAGS	+= --defsym=EFI_SUBSYSTEM=$(SUBSYSTEM)
 endif
 
 FORMAT		?= --target efi-app-$(ARCH)