diff --git a/Makefile b/Makefile
index a243d98..76aea9d 100644
--- a/Makefile
+++ b/Makefile
@@ -236,26 +236,31 @@
 ## Generating/Updating prebuilts
 ##
 
+PREBUILTS_CROSVM_EXT4 := prebuilts/linux-aarch64/images/crosvm.ext4
+PREBUILTS_ROOTFS_EXT4 := prebuilts/linux-aarch64/images/rootfs.ext4
+PREBUILTS_QEMU_ROM := prebuilts/linux-aarch64/images/efi-virtio.rom
+PREBUILTS_QEMU_BIN := prebuilts/linux-x86/qemu
+
 .PHONY:update-prebuilts
 update-prebuilts: \
-	prebuilts/linux-aarch64/images/crosvm.ext4 \
-	prebuilts/linux-aarch64/images/efi-virtio.rom \
-	prebuilts/linux-aarch64/images/rootfs.ext4 \
-	prebuilts/linux-x86/qemu
+	$(PREBUILTS_ROOTFS_EXT4) \
+	$(PREBUILTS_CROSVM_EXT4) \
+	$(PREBUILTS_QEMU_ROM) \
+	$(PREBUILTS_QEMU_BIN)
 
-prebuilts/linux-aarch64/images/rootfs.ext4: buildroot
+$(PREBUILTS_ROOTFS_EXT4): buildroot
 	mkdir -p $(shell dirname $@)
 	cp $(BR_OUT)/images/rootfs.ext4 $@
 
-prebuilts/linux-aarch64/images/efi-virtio.rom: buildroot
+$(PREBUILTS_QEMU_ROM): buildroot
 	mkdir -p $(shell dirname $@)
 	cp $(BR_OUT)/per-package/host-qemu/host/share/qemu/efi-virtio.rom $@
 
 CF_DOWNLOAD_AOSP_SH := $(ROOT_DIR)/build/cuttlefish/download-aosp.sh
 CROSVM_IMG_SIZE_MB := 1024
 
-prebuilts/linux-aarch64/images/crosvm.ext4: TMP_DIR := $(shell mktemp -d)
-prebuilts/linux-aarch64/images/crosvm.ext4: $(CF_DOWNLOAD_AOSP_SH)
+$(PREBUILTS_CROSVM_EXT4): TMP_DIR := $(shell mktemp -d)
+$(PREBUILTS_CROSVM_EXT4): $(CF_DOWNLOAD_AOSP_SH)
 	mkdir -p $(shell dirname $@)
 	cd $(TMP_DIR) && $(CF_DOWNLOAD_AOSP_SH) -a arm64 -C
 	dd if=/dev/zero of=$@.tmp bs=1M count=$(CROSVM_IMG_SIZE_MB)
@@ -264,8 +269,8 @@
 	mv $@.tmp $@
 
 # The qemu binary
-.PHONY:prebuilts/linux-x86/qemu
-prebuilts/linux-x86/qemu:
+.PHONY:$(PREBUILTS_QEMU_BIN)
+$(PREBUILTS_QEMU_BIN):
 	- rm -rf $@
 	${SCRIPTS_DIR}/aarch64/build_qemu.sh $(OUT_DIR)/qemu ${TOOLCHAIN_BIN}
 	mkdir -p $@/bin