diff --git a/src/memfile.c b/src/memfile.c
index dd8dc13..0b3cdd9 100644
--- a/src/memfile.c
+++ b/src/memfile.c
@@ -32,7 +32,7 @@
  * file is opened.
  */
 
-#if defined MSDOS || defined(WIN32) || defined(_WIN64)
+#if defined(MSDOS) || defined(WIN16) || defined(WIN32) || defined(_WIN64)
 # include "vimio.h"	/* for lseek(), must be before vim.h */
 #endif