diff --git a/Makefile.builder b/Makefile.builder
index c19f19c..105d94c 100644
--- a/Makefile.builder
+++ b/Makefile.builder
@@ -1,3 +1,7 @@
-RPM_SPEC_FILES := rpm_spec/qubes-utils.spec rpm_spec/qubes-kernel-vm-support.spec
+SPEC_FILES := rpm_spec/qubes-utils.spec rpm_spec/qubes-kernel-vm-support.spec
+RPM_SPEC_FILES.dom0 := $(if $(filter $(DIST_DOM0), $(DISTS_VM)),, $(SPEC_FILES))
+RPM_SPEC_FILES.vm := $(SPEC_FILES)
+RPM_SPEC_FILES := $(RPM_SPEC_FILES.$(PACKAGE_SET))
+
 ARCH_BUILD_DIRS := archlinux
 DEBIAN_BUILD_DIRS := debian