diff --git a/src/proto/mouse.pro b/src/proto/mouse.pro
index 2127d82..ead8184 100644
--- a/src/proto/mouse.pro
+++ b/src/proto/mouse.pro
@@ -21,6 +21,6 @@
 int check_termcode_mouse(char_u *tp, int *slen, char_u *key_name, char_u *modifiers_start, int idx, int *modifiers);
 int mouse_comp_pos(win_T *win, int *rowp, int *colp, linenr_T *lnump, int *plines_cache);
 win_T *mouse_find_win(int *rowp, int *colp, mouse_find_T popup);
-int vcol2col(win_T *wp, linenr_T lnum, int vcol);
+int vcol2col(win_T *wp, linenr_T lnum, int vcol, colnr_T *coladdp);
 void f_getmousepos(typval_T *argvars, typval_T *rettv);
 /* vim: set ft=c : */