Index: Makefile
===================================================================
--- Makefile    (revision 529225)
+++ Makefile    (working copy)
@@ -18,7 +18,7 @@
 LIB_DEPENDS=   libgmp.so:math/gmp \
                libmpfr.so:math/mpfr
 
-USES=          gmake
+USES=          compiler:c++11-lang gmake
 GNU_CONFIGURE= yes
 CONFIGURE_ARGS=        --disable-static
 USE_GITHUB=    yes