Index: Makefile
===================================================================
--- Makefile	(revision 509488)
+++ Makefile	(working copy)
@@ -13,6 +13,8 @@
 _MAKE_JOBS=	#
 MAKEFILE=	#
 
+USES=		compiler:c++11-lang
+
 WRKSRC_SUBDIR=	tools/build/src/engine
 
 .include "${.CURDIR}/../boost-all/common.mk"