diff --git a/posix.c b/posix.c
index 4b8fde1..3d698aa 100644
--- a/posix.c
+++ b/posix.c
@@ -27,7 +27,7 @@ int mkdir_r_port(const char *const dir, const int flags)
 
         if (stat(dir, &sb))
             return -1;
-        else if (!(sb.st_mode & S_IFDIR))
+        else if (!S_ISDIR(sb.st_mode))
         {
             errno = ENOTDIR;
             return -1;