diff --git a/Makefile b/Makefile
index 3206b63..b782fb3 100644
--- a/Makefile
+++ b/Makefile
@@ -4,28 +4,28 @@ PACKAGE=proxmox-archive-keyring
 
 GITVERSION:=$(shell git rev-parse HEAD)
 
-DEB=${PACKAGE}_${DEB_VERSION_UPSTREAM_REVISION}_all.deb
+DEB=$(PACKAGE)_$(DEB_VERSION_UPSTREAM_REVISION)_all.deb
 
 BUILD_DIR=build
 
 all: deb
-deb: ${DEB}
+deb: $(DEB)
 
-${DEB}: debian
-	rm -rf ${BUILD_DIR}
-	mkdir -p ${BUILD_DIR}/debian
-	cp -ar debian/* ${BUILD_DIR}/debian/
-	echo "git clone git://git.proxmox.com/git/proxmox-archive-keyring.git\\ngit checkout ${GITVERSION}" > ${BUILD_DIR}/debian/SOURCE
-	cd ${BUILD_DIR}; dpkg-buildpackage -b -uc -us
-	lintian ${DEB}
+$(DEB): debian
+	rm -rf $(BUILD_DIR)
+	mkdir -p $(BUILD_DIR)/debian
+	cp -ar debian/* $(BUILD_DIR)/debian/
+	echo "git clone git://git.proxmox.com/git/proxmox-archive-keyring.git\\ngit checkout $(GITVERSION)" > $(BUILD_DIR)/debian/SOURCE
+	cd $(BUILD_DIR); dpkg-buildpackage -b -uc -us
+	lintian $(DEB)
 
 .PHONY: upload
-upload: ${DEB}
-	tar cf - ${DEB}|ssh repoman@repo.proxmox.com -- upload --product pve,pmg,pbs,pbs-client,infra --dist bookworm
+upload: $(DEB)
+	tar cf - $(DEB)|ssh repoman@repo.proxmox.com -- upload --product pve,pmg,pbs,pbs-client,infra --dist bookworm
 
 .PHONY: distclean
 distclean: clean
 
 .PHONY: clean
 clean:
-	rm -rf *~ ${BUILD_DIR} *.deb *.dsc *.changes *.buildinfo
+	rm -rf *~ $(BUILD_DIR) *.deb *.dsc *.changes *.buildinfo