diff --git a/share/mk/src.sys.obj.mk b/share/mk/src.sys.obj.mk
index 708559edcdb8..e4c31f746f3d 100644
--- a/share/mk/src.sys.obj.mk
+++ b/share/mk/src.sys.obj.mk
@@ -94,6 +94,9 @@ OBJTOP:=	${OBJROOT}${MACHINE}.${MACHINE_ARCH}
 # TARGET.TARGET_ARCH handled in OBJROOT already.
 OBJTOP:=	${OBJROOT:H}
 .endif	# ${MK_UNIFIED_OBJDIR} == "yes"
+.if ${.MAKE.LEVEL} > 0
+.export OBJTOP
+.endif
 .endif	# empty(OBJTOP)
 
 # Fixup OBJROOT/OBJTOP if using MAKEOBJDIRPREFIX.