diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index 0c01b526ebf..988c532c4e2 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -1476,6 +1476,52 @@ AC_DEFUN([GLIBCXX_ENABLE_C99], [
       fi
     fi
 
+    # Check for the existence of <ctype.h> functions.
+    AC_CACHE_CHECK([for ISO C99 support for C++11 in <ctype.h>],
+    glibcxx_cv_c99_ctype, [
+    AC_TRY_COMPILE([#include <ctype.h>],
+		   [int ch;
+		    int ret;
+		    ret = isblank(ch);
+		   ],[glibcxx_cv_c99_ctype=yes],
+		     [glibcxx_cv_c99_ctype=no])
+    ])
+    if test x"$glibcxx_cv_c99_ctype" = x"yes"; then
+      AC_DEFINE(_GLIBCXX_USE_C99_CTYPE, 1,
+		[Define if C99 functions in <ctype.h> should be imported in
+		<cctype> in namespace std for C++11.])
+    fi
+
+    # Check for the existence of <fenv.h> functions.
+    AC_CHECK_HEADERS(fenv.h, ac_has_fenv_h=yes, ac_has_fenv_h=no)
+    ac_c99_fenv=no;
+    if test x"$ac_has_fenv_h" = x"yes"; then
+      AC_MSG_CHECKING([for ISO C99 support for C++11 in <fenv.h>])
+      AC_TRY_COMPILE([#include <fenv.h>],
+		     [int except, mode;
+		      fexcept_t* pflag;
+		      fenv_t* penv;
+		      int ret;
+		      ret = feclearexcept(except);
+		      ret = fegetexceptflag(pflag, except);
+		      ret = feraiseexcept(except);
+		      ret = fesetexceptflag(pflag, except);
+		      ret = fetestexcept(except);
+		      ret = fegetround();
+		      ret = fesetround(mode);
+		      ret = fegetenv(penv);
+		      ret = feholdexcept(penv);
+		      ret = fesetenv(penv);
+		      ret = feupdateenv(penv);
+		     ],[ac_c99_fenv=yes], [ac_c99_fenv=no])
+      AC_MSG_RESULT($ac_c99_fenv)
+    fi
+    if test x"$ac_c99_fenv" = x"yes"; then
+      AC_DEFINE(_GLIBCXX_USE_C99_FENV, 1,
+		[Define if C99 functions in <fenv.h> should be imported in
+		<cfenv> in namespace std for C++11.])
+    fi
+
     gcc_no_link="$ac_save_gcc_no_link"
     LIBS="$ac_save_LIBS"
     CXXFLAGS="$ac_save_CXXFLAGS"
diff --git a/libstdc++-v3/config.h.in b/libstdc++-v3/config.h.in
index 62be4c79945..f91f7eb9097 100644
--- a/libstdc++-v3/config.h.in
+++ b/libstdc++-v3/config.h.in
@@ -902,10 +902,18 @@
    library functions to be present. */
 #undef _GLIBCXX_USE_C99_COMPLEX_TR1
 
+/* Define if C99 functions in <ctype.h> should be imported in <cctype> in
+   namespace std for C++11. */
+#undef _GLIBCXX_USE_C99_CTYPE
+
 /* Define if C99 functions in <ctype.h> should be imported in <tr1/cctype> in
    namespace std::tr1. */
 #undef _GLIBCXX_USE_C99_CTYPE_TR1
 
+/* Define if C99 functions in <fenv.h> should be imported in <cfenv> in
+   namespace std for C++11. */
+#undef _GLIBCXX_USE_C99_FENV
+
 /* Define if C99 functions in <fenv.h> should be imported in <tr1/cfenv> in
    namespace std::tr1. */
 #undef _GLIBCXX_USE_C99_FENV_TR1
diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index 26bc090deb1..a9589d882e6 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -18824,6 +18824,103 @@ $as_echo "#define _GLIBCXX11_USE_C99_WCHAR 1" >>confdefs.h
       fi
     fi
 
+    # Check for the existence of <ctype.h> functions.
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for ISO C99 support for C++11 in <ctype.h>" >&5
+$as_echo_n "checking for ISO C99 support for C++11 in <ctype.h>... " >&6; }
+if ${glibcxx_cv_c99_ctype+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <ctype.h>
+int
+main ()
+{
+int ch;
+		    int ret;
+		    ret = isblank(ch);
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  glibcxx_cv_c99_ctype=yes
+else
+  glibcxx_cv_c99_ctype=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $glibcxx_cv_c99_ctype" >&5
+$as_echo "$glibcxx_cv_c99_ctype" >&6; }
+    if test x"$glibcxx_cv_c99_ctype" = x"yes"; then
+
+$as_echo "#define _GLIBCXX_USE_C99_CTYPE 1" >>confdefs.h
+
+    fi
+
+    # Check for the existence of <fenv.h> functions.
+    for ac_header in fenv.h
+do :
+  ac_fn_cxx_check_header_mongrel "$LINENO" "fenv.h" "ac_cv_header_fenv_h" "$ac_includes_default"
+if test "x$ac_cv_header_fenv_h" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_FENV_H 1
+_ACEOF
+ ac_has_fenv_h=yes
+else
+  ac_has_fenv_h=no
+fi
+
+done
+
+    ac_c99_fenv=no;
+    if test x"$ac_has_fenv_h" = x"yes"; then
+      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for ISO C99 support for C++11 in <fenv.h>" >&5
+$as_echo_n "checking for ISO C99 support for C++11 in <fenv.h>... " >&6; }
+      cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <fenv.h>
+int
+main ()
+{
+int except, mode;
+		      fexcept_t* pflag;
+		      fenv_t* penv;
+		      int ret;
+		      ret = feclearexcept(except);
+		      ret = fegetexceptflag(pflag, except);
+		      ret = feraiseexcept(except);
+		      ret = fesetexceptflag(pflag, except);
+		      ret = fetestexcept(except);
+		      ret = fegetround();
+		      ret = fesetround(mode);
+		      ret = fegetenv(penv);
+		      ret = feholdexcept(penv);
+		      ret = fesetenv(penv);
+		      ret = feupdateenv(penv);
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+  ac_c99_fenv=yes
+else
+  ac_c99_fenv=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+      { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_c99_fenv" >&5
+$as_echo "$ac_c99_fenv" >&6; }
+    fi
+    if test x"$ac_c99_fenv" = x"yes"; then
+
+$as_echo "#define _GLIBCXX_USE_C99_FENV 1" >>confdefs.h
+
+    fi
+
     gcc_no_link="$ac_save_gcc_no_link"
     LIBS="$ac_save_LIBS"
     CXXFLAGS="$ac_save_CXXFLAGS"
diff --git a/libstdc++-v3/include/c_compatibility/fenv.h b/libstdc++-v3/include/c_compatibility/fenv.h
index 70ce3f834f4..83e930f12d1 100644
--- a/libstdc++-v3/include/c_compatibility/fenv.h
+++ b/libstdc++-v3/include/c_compatibility/fenv.h
@@ -38,7 +38,7 @@
 
 #if __cplusplus >= 201103L
 
-#if _GLIBCXX_USE_C99_FENV_TR1
+#if _GLIBCXX_USE_C99_FENV
 
 #undef feclearexcept
 #undef fegetexceptflag
@@ -74,7 +74,7 @@ namespace std
   using ::feupdateenv;
 } // namespace
 
-#endif // _GLIBCXX_USE_C99_FENV_TR1
+#endif // _GLIBCXX_USE_C99_FENV
 
 #endif // C++11
 
diff --git a/libstdc++-v3/include/c_global/cctype b/libstdc++-v3/include/c_global/cctype
index bd667fba15d..e6ff1204df6 100644
--- a/libstdc++-v3/include/c_global/cctype
+++ b/libstdc++-v3/include/c_global/cctype
@@ -78,7 +78,7 @@ namespace std
 
 #if __cplusplus >= 201103L
 
-#ifdef _GLIBCXX_USE_C99_CTYPE_TR1
+#ifdef _GLIBCXX_USE_C99_CTYPE
 
 #undef isblank
 
@@ -87,7 +87,7 @@ namespace std
   using ::isblank;
 } // namespace std
 
-#endif // _GLIBCXX_USE_C99_CTYPE_TR1
+#endif // _GLIBCXX_USE_C99_CTYPE
 
 #endif // C++11
 
diff --git a/libstdc++-v3/include/c_global/cfenv b/libstdc++-v3/include/c_global/cfenv
index 6704dc5423e..3a1d9c4a6aa 100644
--- a/libstdc++-v3/include/c_global/cfenv
+++ b/libstdc++-v3/include/c_global/cfenv
@@ -41,7 +41,7 @@
 # include <fenv.h>
 #endif
 
-#ifdef _GLIBCXX_USE_C99_FENV_TR1
+#ifdef _GLIBCXX_USE_C99_FENV
 
 #undef feclearexcept
 #undef fegetexceptflag
@@ -77,7 +77,7 @@ namespace std
   using ::feupdateenv;
 } // namespace std
 
-#endif // _GLIBCXX_USE_C99_FENV_TR1
+#endif // _GLIBCXX_USE_C99_FENV
 
 #endif // C++11