diff --git a/include/boost/system/detail/system_category_win32.hpp b/include/boost/system/detail/system_category_win32.hpp
index 99d0990..ff07ac2 100644
--- a/include/boost/system/detail/system_category_win32.hpp
+++ b/include/boost/system/detail/system_category_win32.hpp
@@ -12,6 +12,7 @@
 #include <boost/winapi/error_codes.hpp>
 #include <boost/winapi/error_handling.hpp>
 #include <boost/winapi/character_code_conversion.hpp>
+#include <boost/winapi/local_memory.hpp>
 
 //
 
@@ -86,10 +87,63 @@ inline char const * system_category_message_win32( int ev, char * buffer, std::s
     return buffer;
 }
 
+struct local_free
+{
+    void * p_;
+
+    ~local_free()
+    {
+        boost::winapi::LocalFree( p_ );
+    }
+};
+
 inline std::string system_category_message_win32( int ev )
 {
-    char buffer[ 256 ];
-    return system_category_message_win32( ev, buffer, sizeof( buffer ) );
+    using namespace boost::winapi;
+
+    void * lpMsgBuf = 0;
+
+    DWORD_ retval = boost::winapi::FormatMessageW(
+        FORMAT_MESSAGE_ALLOCATE_BUFFER_ | FORMAT_MESSAGE_FROM_SYSTEM_ | FORMAT_MESSAGE_IGNORE_INSERTS_,
+        NULL,
+        ev,
+        MAKELANGID_( LANG_NEUTRAL_, SUBLANG_DEFAULT_ ), // Default language
+        (LPWSTR_) &lpMsgBuf,
+        0,
+        NULL
+    );
+
+    local_free lf_ = { lpMsgBuf };
+
+    if( retval == 0 )
+    {
+        return "Unknown error";
+    }
+
+    std::string buffer( retval * 2 + 1, char() );
+
+    int r = boost::winapi::WideCharToMultiByte( CP_ACP_, 0, static_cast<wchar_t const*>( lpMsgBuf ), -1, &buffer[0], static_cast<int>( buffer.size() ), NULL, NULL );
+
+    if( r == 0 )
+    {
+        return "Unknown error";
+    }
+
+    --r; // exclude null terminator
+
+    while( r > 0 && ( buffer[ r-1 ] == '\n' || buffer[ r-1 ] == '\r' ) )
+    {
+        --r;
+    }
+
+    if( r > 0 && buffer[ r-1 ] == '.' )
+    {
+        --r;
+    }
+
+    buffer.resize( r );
+
+    return buffer;
 }
 
 inline error_condition system_category_default_error_condition_win32( int ev ) BOOST_NOEXCEPT
diff --git a/test/Jamfile.v2 b/test/Jamfile.v2
index 893f364..7fbff70 100644
--- a/test/Jamfile.v2
+++ b/test/Jamfile.v2
@@ -125,6 +125,7 @@ system-run win32_hresult_test.cpp ;
 
 system-run error_category_test.cpp ;
 system-run generic_category_test.cpp ;
+system-run system_category_test.cpp ;
 
 # Quick (CI) test
 run quick.cpp ;
diff --git a/test/generic_category_test.cpp b/test/generic_category_test.cpp
index 63e813a..0d53815 100644
--- a/test/generic_category_test.cpp
+++ b/test/generic_category_test.cpp
@@ -25,7 +25,7 @@ int main()
 
     // message
 
-    for( int i = -1; i < 1024; ++i )
+    for( int i = -2; i < 1024; ++i )
     {
         {
             BOOST_TEST_CSTR_EQ( cat.message( i ).c_str(), std::strerror( i ) );
diff --git a/test/system_category_test.cpp b/test/system_category_test.cpp
new file mode 100644
index 0000000..663fae7
--- /dev/null
+++ b/test/system_category_test.cpp
@@ -0,0 +1,112 @@
+
+// Copyright 2018 Peter Dimov.
+//
+// Distributed under the Boost Software License, Version 1.0.
+//
+// See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt
+
+// See library home page at http://www.boost.org/libs/system
+
+// Avoid spurious VC++ warnings
+# define _CRT_SECURE_NO_WARNINGS
+
+#include <boost/system/error_code.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <cstring>
+
+//
+
+#if defined(BOOST_WINDOWS_API)
+
+#include <windows.h>
+
+std::string sys_strerror( int ev )
+{
+    void * lpMsgBuf = 0;
+
+    DWORD retval = FormatMessageA(
+        FORMAT_MESSAGE_ALLOCATE_BUFFER |
+        FORMAT_MESSAGE_FROM_SYSTEM |
+        FORMAT_MESSAGE_IGNORE_INSERTS,
+        NULL,
+        ev,
+        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+        (LPSTR) &lpMsgBuf,
+        0,
+        NULL
+    );
+
+    struct local_free
+    {
+        void * p_;
+
+        ~local_free()
+        {
+            LocalFree( p_ );
+        }
+    };
+
+    local_free lf_ = { lpMsgBuf };
+
+    if( retval == 0 )
+    {
+        return "Unknown error";
+    }
+
+    std::string str( static_cast<char const*>( lpMsgBuf ) );
+
+    while( !str.empty() && (str[str.size()-1] == '\n' || str[str.size()-1] == '\r') )
+    {
+        str.erase( str.size()-1 );
+    }
+
+    if( !str.empty() && str[str.size()-1] == '.' )
+    {
+        str.erase( str.size()-1 );
+    }
+
+    return str;
+}
+
+#else
+
+std::string sys_strerror( int ev )
+{
+    return std::strerror( ev );
+}
+
+#endif
+
+//
+
+namespace sys = boost::system;
+
+static void test_message( sys::error_category const & cat, int ev )
+{
+    BOOST_TEST_EQ( cat.message( ev ), sys_strerror( ev ) );
+
+    char buffer[ 2048 ]; // yes, really
+    BOOST_TEST_CSTR_EQ( cat.message( ev, buffer, sizeof( buffer ) ), sys_strerror( ev ).c_str() );
+}
+
+int main()
+{
+    sys::error_category const & cat = sys::system_category();
+
+    // message
+
+    for( int i = -2; i < 1024; ++i )
+    {
+        test_message( cat, i );
+    }
+
+    test_message( cat, 5810 );
+
+    for( int i = 10000; i < 11032; ++i )
+    {
+        test_message( cat, i );
+    }
+
+    return boost::report_errors();
+}