diff --git a/tools/build/make_check/check.mk b/tools/build/make_check/check.mk
new file mode 100644
index 000000000000..f2d666d5ca43
--- /dev/null
+++ b/tools/build/make_check/check.mk
@@ -0,0 +1,19 @@
+# $FreeBSD$
+
+all:
+	${MK} ${MK_ARG}
+
+.if exists(${.OBJDIR}/../../../usr.bin/make/make)
+MK=	${.OBJDIR}/../../../usr.bin/make/make
+new:
+	${MK} ${MK_ARG} 2>&1 | tee out-new
+	@echo "-=-=-=-=-=-"
+	make ${MK_ARG} 2>&1 | tee out-old
+	@echo "-=-=-=-=-=-"
+	diff -s out-old out-new
+.else
+MK=	make
+.endif
+MK_ARG=	-C ${.CURDIR}
+
+.include <bsd.obj.mk>