diff --git a/share/mk/bsd.own.mk b/share/mk/bsd.own.mk
index 03f6c0b60372..2a79c42e01c7 100644
--- a/share/mk/bsd.own.mk
+++ b/share/mk/bsd.own.mk
@@ -420,15 +420,6 @@ __DEFAULT_YES_OPTIONS+=GCC
 .else
 __DEFAULT_NO_OPTIONS+=GCC GNUCXX
 .endif
-# The libc++ headers use c++11 extensions.  These are normally silenced because
-# they are treated as system headers, but we explicitly disable that warning
-# suppression when building the base system to catch bugs in our headers.
-# Eventually we'll want to start building the base system C++ code as C++11,
-# but not yet.
-_COMPVERSION!= ${CC} --version
-.if ${_COMPVERSION:Mclang}
-CXXFLAGS+=	-Wno-c++11-extensions
-.endif
 .else
 # If clang is not cc, then build gcc by default
 __DEFAULT_NO_OPTIONS+=CLANG_IS_CC
diff --git a/share/mk/bsd.sys.mk b/share/mk/bsd.sys.mk
index 5ba2d5162bb9..7779580214e8 100644
--- a/share/mk/bsd.sys.mk
+++ b/share/mk/bsd.sys.mk
@@ -120,6 +120,12 @@ CLANG_NO_IAS=	 -no-integrated-as
 CLANG_OPT_SMALL= -mstack-alignment=8 -mllvm -inline-threshold=3\
 		 -mllvm -enable-load-pre=false -mllvm -simplifycfg-dup-ret
 CFLAGS+=	 -Qunused-arguments
+# The libc++ headers use c++11 extensions.  These are normally silenced because
+# they are treated as system headers, but we explicitly disable that warning
+# suppression when building the base system to catch bugs in our headers.
+# Eventually we'll want to start building the base system C++ code as C++11,
+# but not yet.
+CXXFLAGS+=	 -Wno-c++11-extensions
 CFLAGS+=	 ${CFLAGS.clang}
 CXXFLAGS+=	 ${CXXFLAGS.clang}
 .else # !CLANG