diff --git a/scripts/package/Makefile b/scripts/package/Makefile
index 87bf08076b11..d7b328595a7e 100644
--- a/scripts/package/Makefile
+++ b/scripts/package/Makefile
@@ -36,7 +36,7 @@ $(objtree)/kernel.spec: $(MKSPEC) $(srctree)/Makefile
 	$(CONFIG_SHELL) $(MKSPEC) > $@
 
 rpm-pkg rpm: $(objtree)/kernel.spec FORCE
-	@if test -n "$(KBUILD_OUTPUT)"; then \
+	@if test "$(objtree)" != "$(srctree)"; then \
 		echo "Building source + binary RPM is not possible outside the"; \
 		echo "kernel source tree. Don't set KBUILD_OUTPUT, or use the"; \
 		echo "binrpm-pkg target instead."; \