Index: Mk/bsd.port.mk
===================================================================
--- Mk/bsd.port.mk	(revision 495831)
+++ Mk/bsd.port.mk	(working copy)
@@ -1029,6 +1029,9 @@
 LC_ALL=		C
 .export		LANG LC_ALL
 
+__MAKE_CONF=	/dev/null
+.export		__MAKE_CONF
+
 # These need to be absolute since we don't know how deep in the ports
 # tree we are and thus can't go relative.  They can, of course, be overridden
 # by individual Makefiles or local system make configuration.