Index: lib/libc++/Makefile
===================================================================
--- lib/libc++/Makefile
+++ lib/libc++/Makefile
@@ -76,7 +76,7 @@
 CFLAGS+=	-nostdlib
 CFLAGS+=	-D_LIBCPP_BUILDING_LIBRARY
 CFLAGS+=	-DLIBCXXRT
-CXXSTD=		c++11
+CXXSTD?=	c++11
 
 LIBADD+=	cxxrt
 INCSGROUPS=	STD EXP EXT
Index: lib/libc++experimental/Makefile
===================================================================
--- lib/libc++experimental/Makefile
+++ lib/libc++experimental/Makefile
@@ -20,6 +20,6 @@
 CXXFLAGS+=	-nostdlib
 CXXFLAGS+=	-D_LIBCPP_BUILDING_LIBRARY
 CXXFLAGS+=	-DLIBCXXRT
-CXXSTD=		c++14
+CXXSTD?=	c++14
 
 .include <bsd.lib.mk>
Index: lib/libc++fs/Makefile
===================================================================
--- lib/libc++fs/Makefile
+++ lib/libc++fs/Makefile
@@ -22,6 +22,6 @@
 CXXFLAGS+=	-nostdlib
 CXXFLAGS+=	-D_LIBCPP_BUILDING_LIBRARY
 CXXFLAGS+=	-DLIBCXXRT
-CXXSTD=		c++14
+CXXSTD?=	c++14
 
 .include <bsd.lib.mk>
Index: lib/libcxxrt/Makefile
===================================================================
--- lib/libcxxrt/Makefile
+++ lib/libcxxrt/Makefile
@@ -22,7 +22,7 @@
 
 WARNS=		0
 CFLAGS+=	-isystem ${SRCDIR} -nostdinc++
-CXXSTD=		c++11
+CXXSTD?=	c++11
 VERSION_MAP=	${.CURDIR}/Version.map
 
 .include <bsd.lib.mk>
Index: lib/libgcc_eh/Makefile.inc
===================================================================
--- lib/libgcc_eh/Makefile.inc
+++ lib/libgcc_eh/Makefile.inc
@@ -28,7 +28,7 @@
 
 CFLAGS+=	-I${UNWINDINCDIR} -I${.CURDIR} -D_LIBUNWIND_IS_NATIVE_ONLY
 CXXFLAGS+=	-fno-rtti
-CXXSTD=		c++11
+CXXSTD?=	c++11
 STATIC_CXXFLAGS+= -fvisibility=hidden -fPIC
 # Probably need to just move this earlier or use CXXFLAGS
 .if ${MK_DIRDEPS_BUILD} == "yes"
Index: lib/ofed/libibnetdisc/Makefile
===================================================================
--- lib/ofed/libibnetdisc/Makefile
+++ lib/ofed/libibnetdisc/Makefile
@@ -31,6 +31,9 @@
 CFLAGS+=	-DHAVE_CONFIG_H=1
 CFLAGS+=	-I${_spath}
 CFLAGS+=	-I${SYSROOT:U${DESTDIR}}/${INCLUDEDIR}/infiniband
+.if ${COMPILER_FEATURES:Mc++11}
+CXXSTD=		c++11
+.endif
 VERSION_MAP=	${_spath}/libibnetdisc.map
 
 .include <bsd.lib.mk>
Index: share/mk/bsd.sys.mk
===================================================================
--- share/mk/bsd.sys.mk
+++ share/mk/bsd.sys.mk
@@ -25,17 +25,9 @@
 CFLAGS+=	-std=${CSTD}
 .endif # CSTD
 
-.if ${COMPILER_FEATURES:Mc++11}
-CXXSTD?=	c++11
-.elif ${COMPILER_TYPE} == "gcc"
-# Prior versions of g++ support C++98 with GNU extensions by default.
-CXXSTD?=	gnu++98
-.else
-# Assume that the compiler supports at least C++98.
-CXXSTD?=	c++98
-.endif
+.if !empty(CXXSTD)
 CXXFLAGS+=	-std=${CXXSTD}
-# CXXSTD
+.endif
 
 # -pedantic is problematic because it also imposes namespace restrictions
 #CFLAGS+=	-pedantic
Index: share/mk/googletest.test.inc.mk
===================================================================
--- share/mk/googletest.test.inc.mk
+++ share/mk/googletest.test.inc.mk
@@ -9,4 +9,6 @@
 # libgmock's, etc, headers.
 CXXFLAGS+=	-I${DESTDIR}${INCLUDEDIR}/private
 
+CXXSTD?=	c++11
+
 NO_WTHREAD_SAFETY=
Index: usr.bin/dtc/Makefile
===================================================================
--- usr.bin/dtc/Makefile
+++ usr.bin/dtc/Makefile
@@ -8,6 +8,8 @@
 
 CXXFLAGS+=	-fno-rtti -fno-exceptions
 
+CXXSTD=	c++11
+
 NO_SHARED?=NO
 
 .include <bsd.prog.mk>