diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index ec9bfd2bd2b896616f17b74c0bb79c5550891a08..60bc7b5a5ebd4909060f3d98e456e1587dbfef64 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,11 @@
+2013-06-11  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR libstdc++/56019
+	* include/c_global/cstddef (max_align_t): Add to namespace std.
+	* include/c_std/cstddef: Likewise.
+	* testsuite/18_support/max_align_t/requirements/1.cc: New.
+	* testsuite/18_support/max_align_t/requirements/2.cc: Likewise.
+
 2013-06-10  Benjamin Kosnik  <bkoz@redhat.com>
 
 	* include/bits/c++config (_GLIBCXX_ABI_TAG_CXX11): Add.
diff --git a/libstdc++-v3/include/c_global/cstddef b/libstdc++-v3/include/c_global/cstddef
index 00660f3a5a4d4b68b0527e54247366c90f08dd6e..94d8957716d05f93a4a162c3db168f6ed0b8dd0b 100644
--- a/libstdc++-v3/include/c_global/cstddef
+++ b/libstdc++-v3/include/c_global/cstddef
@@ -36,7 +36,20 @@
 // ISO C++ 14882: 18.1  Types
 //
 
+#ifndef _GLIBCXX_CSTDDEF
+#define _GLIBCXX_CSTDDEF 1
+
 #pragma GCC system_header
 
 #include <bits/c++config.h>
 #include <stddef.h>
+
+#if __cplusplus >= 201103L
+namespace std
+{
+  // We handle size_t, ptrdiff_t, and nullptr_t in c++config.h.
+  using ::max_align_t;
+}
+#endif
+
+#endif // _GLIBCXX_CSTDDEF
diff --git a/libstdc++-v3/include/c_std/cstddef b/libstdc++-v3/include/c_std/cstddef
index 9500bc514bd63ec361eff63756309a629dbbd576..6f1b5bd5d792c873d5d3bfd423b6f45677449f0e 100644
--- a/libstdc++-v3/include/c_std/cstddef
+++ b/libstdc++-v3/include/c_std/cstddef
@@ -44,4 +44,12 @@
 #include <bits/c++config.h>
 #include <stddef.h>
 
+#if __cplusplus >= 201103L
+namespace std
+{
+  // We handle size_t, ptrdiff_t, and nullptr_t in c++config.h.
+  using ::max_align_t;
+}
 #endif
+
+#endif // _GLIBCXX_CSTDDEF
diff --git a/libstdc++-v3/testsuite/18_support/max_align_t/requirements/1.cc b/libstdc++-v3/testsuite/18_support/max_align_t/requirements/1.cc
new file mode 100644
index 0000000000000000000000000000000000000000..405e097dcc5360f17c5b7b85031bd61f2f391ba2
--- /dev/null
+++ b/libstdc++-v3/testsuite/18_support/max_align_t/requirements/1.cc
@@ -0,0 +1,23 @@
+// { dg-do compile }
+// { dg-options "-std=gnu++11" }
+//
+// Copyright (C) 2013 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <cstddef>
+
+std::max_align_t t;
diff --git a/libstdc++-v3/testsuite/18_support/max_align_t/requirements/2.cc b/libstdc++-v3/testsuite/18_support/max_align_t/requirements/2.cc
new file mode 100644
index 0000000000000000000000000000000000000000..d702720815cd5586d3d7b58913f350dd334711e1
--- /dev/null
+++ b/libstdc++-v3/testsuite/18_support/max_align_t/requirements/2.cc
@@ -0,0 +1,24 @@
+// { dg-do compile }
+// { dg-options "-std=gnu++11" }
+//
+// Copyright (C) 2013 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <cstddef>
+#include <type_traits>
+
+static_assert (std::is_pod<std::max_align_t>::value, "");