diff --git a/science/mdynamix/Makefile b/science/mdynamix/Makefile
index 70e120df00936..aee6bb7186280 100644
--- a/science/mdynamix/Makefile
+++ b/science/mdynamix/Makefile
@@ -11,6 +11,8 @@ WWW=		http://www.fos.su.se/~sasha/mdynamix/
 
 LICENSE=	GPLv2+
 
+BROKEN_FreeBSD_12=	error: invalid value 'gnu++2b' in '-std=gnu++2b'
+
 LIB_DEPENDS=	libmpich.so:net/mpich
 
 USES=		fortran gmake