diff --git a/include/sys/types.h b/include/sys/types.h
index 1efde1f4..f1fcc126 100644
--- a/include/sys/types.h
+++ b/include/sys/types.h
@@ -135,6 +135,15 @@ typedef long ssize_t;
 typedef unsigned uid_t;
 #endif
 
+#ifndef __WCHAR_T
+#define __WCHAR_T
+#ifndef __MES_WCHAR_T
+#define __MES_WCHAR_T
+#undef wchar_t
+typedef int wchar_t;
+#endif
+#endif
+
 #endif // ! WITH_GLIBC
 
 #endif // __MES_SYS_TYPES_H
diff --git a/lib/stdlib/mbstowcs.c b/lib/stdlib/mbstowcs.c
index 9330f355..db67c2d9 100644
--- a/lib/stdlib/mbstowcs.c
+++ b/lib/stdlib/mbstowcs.c
@@ -20,9 +20,6 @@
 
 #include <stdlib.h>
 
-#if !__MESC__
-typedef char wchar_t[];
-
 size_t
 mbstowcs (wchar_t *wstring, char const *string,
           size_t size)
@@ -34,4 +31,3 @@ mbstowcs (wchar_t *wstring, char const *string,
   strcpy (wstring, string);
   return strlen (string);
 }
-#endif