--- Makefile.orig	2018-02-02 21:54:14.606798000 +0700
+++ Makefile	2018-02-02 21:54:32.290823000 +0700
@@ -15,7 +15,7 @@
 
 LIB_DEPENDS=	libprotobuf.so:devel/protobuf
 
-USES=		autoreconf gmake libtool pkgconfig
+USES=		compiler:c++11-lang autoreconf gmake libtool pkgconfig
 GNU_CONFIGURE=	yes
 USE_GITHUB=	yes
 USE_LDCONFIG=	yes