diff --git a/src/os_msdos.c b/src/os_msdos.c
index bd18c84..4563bf1 100644
--- a/src/os_msdos.c
+++ b/src/os_msdos.c
@@ -21,7 +21,7 @@
  * Some functions are also used for Win16 (MS-Windows 3.1).
  */
 
-#include <io.h>
+#include "vimio.h"
 #include "vim.h"
 
 #include <conio.h>