diff --git a/TODO b/TODO
index cdf1866b..3cfc7517 100644
--- a/TODO
+++ b/TODO
@@ -1,3 +1,15 @@
+- on win see:
+
+	vips2tiff:389 unknown control sequence
+	\W \S \s \d \c
+
+	if( !(buffer = vips__file_read_name( profile, VIPS_ICC_DIR, &length )) )
+
+	config.h:#define VIPS_ICC_DIR "C:\Windows\System32\spool\drivers\color"
+
+  hehe argh
+
+
 - add APPROX convsep test? 
 
 - add more webp tests to py suite
diff --git a/configure.ac b/configure.ac
index 9b40cefe..e2df036f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -383,6 +383,17 @@ PKG_CHECK_MODULES(TYPE_INIT, glib-2.0 < 2.36,
   ]
 )
 
+# with 2.40 we have g_win32_get_command_line() on win
+PKG_CHECK_MODULES(TYPE_INIT, glib-2.0 >= 2.40,
+  [if test x"$vips_os_win32" = x"yes"; then
+     AC_DEFINE(HAVE_G_WIN32_GET_COMMAND_LINE,1,[define if your glib has g_win32_get_command_line().])
+     have_g_win32_get_command_line=yes
+   fi
+  ],
+  [:
+  ]
+)
+
 # check for gtk-doc
 GTK_DOC_CHECK([1.14],[--flavour no-tmpl])
 
@@ -1136,3 +1147,11 @@ You may need to copy this file, for example:
       ;;
   esac
 fi
+
+if test x"$vips_os_win32" = x"yes"; then
+  if test x"$have_g_win32_get_command_line" != x"yes"; then
+    AC_MSG_RESULT([dnl
+Your glib is too old, vips will not support unicode command-line arguments.
+    ])
+  fi
+fi
diff --git a/libvips/iofuncs/util.c b/libvips/iofuncs/util.c
index 48158410..823b08bf 100644
--- a/libvips/iofuncs/util.c
+++ b/libvips/iofuncs/util.c
@@ -558,6 +558,41 @@ filename_hasdir( const char *filename )
 	return( hasdir );
 }
 
+/* fopen() with utf8 filename and mode.
+ */
+static FILE *
+vips__fopen( const char *filename, const char *mode )
+{
+	FILE *fp;
+
+#ifdef OS_WIN32
+	GError *error = NULL;
+	wchar_t *path16, *mode16;
+	
+	if( !(path16 = (wchar_t *) 
+		g_utf8_to_utf16( filename, -1, NULL, NULL, &error )) ) { 
+		vips_g_error( error );
+		return( NULL );
+	}
+
+	if( !(mode16 = (wchar_t *) 
+		g_utf8_to_utf16( mode, -1, NULL, NULL, &error )) ) { 
+		g_free( path16 );
+		vips_g_error( error );
+		return( NULL );
+	}
+
+	fp = _wfopen( path16, mode16 );
+
+	g_free( path16 );
+	g_free( mode16 );
+#else /*!OS_WIN32*/
+	fp = fopen( filename, mode );
+#endif
+
+	return( fp );
+}
+
 /* Open a file. We take an optional fallback dir as well and will try opening
  * there if opening directly fails.
  *
@@ -581,7 +616,7 @@ vips__file_open_read( const char *filename, const char *fallback_dir,
 	mode = "r";
 #endif /*BINARY_OPEN*/
 
-	if( (fp = fopen( filename, mode )) )
+	if( (fp = vips__fopen( filename, mode )) )
 		return( fp );
 
 	if( fallback_dir && 
@@ -589,7 +624,7 @@ vips__file_open_read( const char *filename, const char *fallback_dir,
 		char *path;
 
 		path = g_build_filename( fallback_dir, filename, NULL );
-	        fp = fopen( path, mode );
+	        fp = vips__fopen( path, mode );
 		g_free( path );
 
 		if( fp )
@@ -617,7 +652,7 @@ vips__file_open_write( const char *filename, gboolean text_mode )
 	mode = "w";
 #endif /*BINARY_OPEN*/
 
-        if( !(fp = fopen( filename, mode )) ) {
+        if( !(fp = vips__fopen( filename, mode )) ) {
 		vips_error_system( errno, "vips__file_open_write", 
 			_( "unable to open file \"%s\" for writing" ), 
 			filename );
diff --git a/tools/vipsthumbnail.c b/tools/vipsthumbnail.c
index b6199d87..17dd8235 100644
--- a/tools/vipsthumbnail.c
+++ b/tools/vipsthumbnail.c
@@ -680,6 +680,14 @@ main( int argc, char **argv )
 	textdomain( GETTEXT_PACKAGE );
 	setlocale( LC_ALL, "" );
 
+	/* On Windows, argv is ascii-only .. use this to get a utf-8 version of
+	 * the args.
+	 */
+#ifdef HAVE_G_WIN32_GET_COMMAND_LINE
+	printf( "using g_win32_get_command_line()\n" ); 
+	argv = g_win32_get_command_line();
+#endif /*HAVE_G_WIN32_GET_COMMAND_LINE*/
+
         context = g_option_context_new( _( "- thumbnail generator" ) );
 
 	main_group = g_option_group_new( NULL, NULL, NULL, NULL, NULL );
@@ -738,6 +746,12 @@ main( int argc, char **argv )
 		g_object_unref( process );
 	}
 
+	/* We don't free this on error exit, sadly.
+	 */
+#ifdef HAVE_G_WIN32_GET_COMMAND_LINE
+	g_strfreev( argv ); 
+#endif /*HAVE_G_WIN32_GET_COMMAND_LINE*/
+
 	vips_shutdown();
 
 	return( result );