diff --git a/reactos/lib/sdk/crt/string/_tsplitpath_x.h b/reactos/lib/sdk/crt/string/_tsplitpath_x.h
index 0e35a25656c..c8c89e4d52c 100644
--- a/reactos/lib/sdk/crt/string/_tsplitpath_x.h
+++ b/reactos/lib/sdk/crt/string/_tsplitpath_x.h
@@ -106,7 +106,7 @@ _tsplitpath_x(
     dir_start = path;
     while (*path != '\0')
     {
-#ifndef _UNICODE
+#if !defined(_UNICODE) && !defined(_LIBCNT_)
         /* Check for multibyte lead bytes */
         if (_ismbblead((unsigned char)*path))
         {