diff --git a/lib/libc++/Makefile b/lib/libc++/Makefile
index d83c4f81c016..f8c8da4f2035 100644
--- a/lib/libc++/Makefile
+++ b/lib/libc++/Makefile
@@ -76,7 +76,7 @@ CFLAGS+=	-nostdinc++
 CFLAGS+=	-nostdlib
 CFLAGS+=	-D_LIBCPP_BUILDING_LIBRARY
 CFLAGS+=	-DLIBCXXRT
-CXXSTD=		c++11
+CXXSTD?=	c++11
 
 LIBADD+=	cxxrt
 INCSGROUPS=	STD EXP EXT
diff --git a/lib/libc++experimental/Makefile b/lib/libc++experimental/Makefile
index 53c33018b535..b75f82a1259a 100644
--- a/lib/libc++experimental/Makefile
+++ b/lib/libc++experimental/Makefile
@@ -20,6 +20,6 @@ CXXFLAGS+=	-nostdinc++
 CXXFLAGS+=	-nostdlib
 CXXFLAGS+=	-D_LIBCPP_BUILDING_LIBRARY
 CXXFLAGS+=	-DLIBCXXRT
-CXXSTD=		c++14
+CXXSTD?=	c++14
 
 .include <bsd.lib.mk>
diff --git a/lib/libc++fs/Makefile b/lib/libc++fs/Makefile
index ede7d1687d4d..01105375a71b 100644
--- a/lib/libc++fs/Makefile
+++ b/lib/libc++fs/Makefile
@@ -22,6 +22,6 @@ CXXFLAGS+=	-nostdinc++
 CXXFLAGS+=	-nostdlib
 CXXFLAGS+=	-D_LIBCPP_BUILDING_LIBRARY
 CXXFLAGS+=	-DLIBCXXRT
-CXXSTD=		c++14
+CXXSTD?=	c++14
 
 .include <bsd.lib.mk>
diff --git a/lib/libcxxrt/Makefile b/lib/libcxxrt/Makefile
index 49d632650c35..b1c62e3255e2 100644
--- a/lib/libcxxrt/Makefile
+++ b/lib/libcxxrt/Makefile
@@ -22,7 +22,7 @@ SRCS+=		libelftc_dem_gnu3.c\
 
 WARNS=		0
 CFLAGS+=	-isystem ${SRCDIR} -nostdinc++
-CXXSTD=		c++11
+CXXSTD?=	c++11
 VERSION_MAP=	${.CURDIR}/Version.map
 
 .include <bsd.lib.mk>
diff --git a/lib/libgcc_eh/Makefile.inc b/lib/libgcc_eh/Makefile.inc
index 39cccec7e6d9..232f5d8d46fa 100644
--- a/lib/libgcc_eh/Makefile.inc
+++ b/lib/libgcc_eh/Makefile.inc
@@ -28,7 +28,7 @@ CXXFLAGS.${file}+=	-fno-exceptions -funwind-tables
 
 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 ${MK_DIRDEPS_BUILD} == "yes"
diff --git a/lib/ofed/libibnetdisc/Makefile b/lib/ofed/libibnetdisc/Makefile
index 08dbb8861407..0736ae93f12f 100644
--- a/lib/ofed/libibnetdisc/Makefile
+++ b/lib/ofed/libibnetdisc/Makefile
@@ -31,6 +31,9 @@ LIBADD=		osmcomp ibmad ibumad
 CFLAGS+=	-DHAVE_CONFIG_H=1
 CFLAGS+=	-I${_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>
diff --git a/usr.bin/dtc/Makefile b/usr.bin/dtc/Makefile
index 92769609d034..897b74e188de 100644
--- a/usr.bin/dtc/Makefile
+++ b/usr.bin/dtc/Makefile
@@ -8,6 +8,8 @@ WARNS?=	3
 
 CXXFLAGS+=	-fno-rtti -fno-exceptions
 
+CXXSTD=	c++11
+
 NO_SHARED?=NO
 
 .include <bsd.prog.mk>