diff --git a/libstdc++-v3/include/std/span b/libstdc++-v3/include/std/span
index fb349403c9ee..24c61ba41728 100644
--- a/libstdc++-v3/include/std/span
+++ b/libstdc++-v3/include/std/span
@@ -38,8 +38,8 @@
 
 #if __cplusplus > 201703L
 
-#include <type_traits>
 #include <array>
+#include <cstddef>
 #include <bits/stl_iterator.h>
 #include <bits/ranges_base.h>
 
@@ -151,7 +151,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       constexpr
       span() noexcept
       requires ((_Extent + 1u) <= 1u)
-      : _M_extent(0), _M_ptr(nullptr)
+      : _M_ptr(nullptr), _M_extent(0)
       { }
 
       template<contiguous_iterator _It>
@@ -159,7 +159,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	constexpr explicit(extent != dynamic_extent)
 	span(_It __first, size_type __count)
 	noexcept
-	: _M_extent(__count), _M_ptr(std::to_address(__first))
+	: _M_ptr(std::to_address(__first)), _M_extent(__count)
 	{
 	  if constexpr (_Extent != dynamic_extent)
 	    {
@@ -173,8 +173,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	constexpr explicit(extent != dynamic_extent)
 	span(_It __first, _End __last)
 	noexcept(noexcept(__last - __first))
-	: _M_extent(static_cast<size_type>(__last - __first)),
-	  _M_ptr(std::to_address(__first))
+	: _M_ptr(std::to_address(__first)),
+	  _M_extent(static_cast<size_type>(__last - __first))
 	{
 	  if constexpr (_Extent != dynamic_extent)
 	    {
@@ -392,8 +392,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       }
 
     private:
-      [[no_unique_address]] __detail::__extent_storage<extent> _M_extent;
       pointer _M_ptr;
+      [[no_unique_address]] __detail::__extent_storage<extent> _M_extent;
     };
 
   // deduction guides
diff --git a/libstdc++-v3/testsuite/23_containers/span/layout_compat.cc b/libstdc++-v3/testsuite/23_containers/span/layout_compat.cc
new file mode 100644
index 000000000000..efc5b8e4706b
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/span/layout_compat.cc
@@ -0,0 +1,48 @@
+// Copyright (C) 2020 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/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do compile { target c++2a } }
+
+#include <span>
+#include <cstddef>
+
+#if __has_include(<sys/uio.h>)
+#include <sys/uio.h>
+#else
+struct iovec { void* iov_base; std::size_t iov_len; };
+#endif
+
+#if __cpp_lib_is_pointer_interconvertible
+using std::is_layout_compatible_v;
+#else
+// A poor substitute for is_layout_compatible_v
+template<typename T, typename U>
+  constexpr bool is_layout_compatible_v
+    = std::is_standard_layout_v<T> && std::is_standard_layout_v<U>
+      && sizeof(T) == sizeof(U) && alignof(T) == alignof(U);
+#endif
+
+void
+test_pr95609()
+{
+  using rbuf = std::span<const std::byte>;
+  using wbuf = std::span<std::byte>;
+
+  static_assert(is_layout_compatible_v<rbuf, struct iovec>);
+  static_assert(is_layout_compatible_v<wbuf, struct iovec>);
+}