diff --git a/src/proto/screen.pro b/src/proto/screen.pro
index de42c43..66fc0f3 100644
--- a/src/proto/screen.pro
+++ b/src/proto/screen.pro
@@ -55,5 +55,5 @@
 int number_width(win_T *wp);
 int screen_screencol(void);
 int screen_screenrow(void);
-char *set_chars_option(win_T *wp, char_u **varp);
+char *set_chars_option(win_T *wp, char_u **varp, int apply);
 /* vim: set ft=c : */