diff -uNr gtk-3.22.30/m4/wchar_t.m4 gtk-3.22.30.mod/m4/wchar_t.m4
--- gtk-3.22.30/m4/wchar_t.m4	1970-01-01 03:00:00.000000000 +0300
+++ gtk-3.22.30.mod/m4/wchar_t.m4	2018-06-22 20:55:46.581292922 +0300
@@ -0,0 +1,24 @@
+# wchar_t.m4 serial 4 (gettext-0.18.2)
+dnl Copyright (C) 2002-2003, 2008-2015 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Bruno Haible.
+dnl Test whether <stddef.h> has the 'wchar_t' type.
+dnl Prerequisite: AC_PROG_CC
+
+AC_DEFUN([gt_TYPE_WCHAR_T],
+[
+  AC_CACHE_CHECK([for wchar_t], [gt_cv_c_wchar_t],
+    [AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[#include <stddef.h>
+            wchar_t foo = (wchar_t)'\0';]],
+          [[]])],
+       [gt_cv_c_wchar_t=yes],
+       [gt_cv_c_wchar_t=no])])
+  if test $gt_cv_c_wchar_t = yes; then
+    AC_DEFINE([HAVE_WCHAR_T], [1], [Define if you have the 'wchar_t' type.])
+  fi
+])