Index: net/openmpi/Makefile
===================================================================
--- net/openmpi/Makefile
+++ net/openmpi/Makefile
@@ -22,7 +22,8 @@
 HAS_CONFIGURE=	yes
 INSTALL_TARGET=	install-strip
 # :keepla because port uses lt_dlopen
-USES=		fortran gmake libtool:keepla perl5 pkgconfig tar:bzip2
+USES=		compiler:c11 fortran gmake libtool:keepla perl5 pkgconfig \
+		tar:bzip2
 USE_PERL5=	build
 
 MPIBASE?=	mpi