diff --git a/roms/Makefile b/roms/Makefile
index 78d5dd1..d28252d 100644
--- a/roms/Makefile
+++ b/roms/Makefile
@@ -47,7 +47,7 @@
 # We need that to combine multiple images (legacy bios,
 # efi ia32, efi x64) into a single rom binary.
 #
-EFIROM = edk2/BaseTools/Source/C/bin/EfiRom
+EDK2_EFIROM = edk2/BaseTools/Source/C/bin/EfiRom
 
 default:
 	@echo "nothing is build by default"
@@ -102,8 +102,8 @@
 
 efirom: $(patsubst %,efi-rom-%,$(pxerom_variants))
 
-efi-rom-%: build-pxe-roms build-efi-roms $(EFIROM)
-	$(EFIROM) -f "0x$(VID)" -i "0x$(DID)" -l 0x02 \
+efi-rom-%: build-pxe-roms build-efi-roms $(EDK2_EFIROM)
+	$(EDK2_EFIROM) -f "0x$(VID)" -i "0x$(DID)" -l 0x02 \
 		-b ipxe/src/bin/$(VID)$(DID).rom \
 		-ec ipxe/src/bin-i386-efi/$(VID)$(DID).efidrv \
 		-ec ipxe/src/bin-x86_64-efi/$(VID)$(DID).efidrv \
@@ -120,7 +120,7 @@
 		$(patsubst %,bin-i386-efi/%.efidrv,$(pxerom_targets)) \
 		$(patsubst %,bin-x86_64-efi/%.efidrv,$(pxerom_targets))
 
-$(EFIROM):
+$(EDK2_EFIROM):
 	$(MAKE) -C edk2/BaseTools
 
 slof: