diff --git a/src/window.c b/src/window.c
index ae17660..ee69921 100644
--- a/src/window.c
+++ b/src/window.c
@@ -6438,7 +6438,7 @@
 	/* something failed; use the file name (truncate when too long) */
 	vim_strncpy(buf, fname, len - 1);
     }
-#if defined(MACOS_CLASSIC) || defined(MSDOS) || defined(MSWIN)
+#if defined(MACOS_CLASSIC) || defined(MSWIN)
     slash_adjust(buf);
 #endif
     return retval;