diff --git a/libcxx/include/cstdalign b/libcxx/include/cstdalign
new file mode 100644
--- /dev/null
+++ b/libcxx/include/cstdalign
@@ -0,0 +1,33 @@
+// -*- C++ -*-
+//===--------------------------- cstdalign --------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CSTDALIGN
+#define _LIBCPP_CSTDALIGN
+
+/*
+    cstdalign synopsis
+
+Macros:
+
+   alignof
+   alignas
+    __alignof_is_defined
+    __alignas_is_defined
+
+*/
+
+#include <__config>
+#include <stdalign.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+#endif  // _LIBCPP_CSTDALIGN
diff --git a/libcxx/test/libcxx/min_max_macros.compile.pass.cpp b/libcxx/test/libcxx/min_max_macros.compile.pass.cpp
--- a/libcxx/test/libcxx/min_max_macros.compile.pass.cpp
+++ b/libcxx/test/libcxx/min_max_macros.compile.pass.cpp
@@ -96,6 +96,8 @@
 TEST_MACROS();
 #include <csignal>
 TEST_MACROS();
+#include <cstdalign>
+TEST_MACROS();
 #include <cstdarg>
 TEST_MACROS();
 #include <cstdbool>
diff --git a/libcxx/test/libcxx/utilities/any/size_and_alignment.pass.cpp b/libcxx/test/libcxx/utilities/any/size_and_alignment.pass.cpp
--- a/libcxx/test/libcxx/utilities/any/size_and_alignment.pass.cpp
+++ b/libcxx/test/libcxx/utilities/any/size_and_alignment.pass.cpp
@@ -13,6 +13,7 @@
 // Check that the size and alignment of any are what we expect.
 
 #include <any>
+#include <cstdalign>
 
 #include "test_macros.h"