diff --git a/src/option.h b/src/option.h
index d994d2d..7da6b8a 100644
--- a/src/option.h
+++ b/src/option.h
@@ -671,7 +671,7 @@
 #ifdef FEAT_MZSCHEME
 EXTERN long	p_mzq;		/* 'mzquantum */
 #endif
-#if defined(MSDOS) || defined(MSWIN) || defined(OS2)
+#if defined(MSDOS) || defined(MSWIN)
 EXTERN int	p_odev;		/* 'opendevice' */
 #endif
 EXTERN char_u	*p_opfunc;	/* 'operatorfunc' */