diff --git a/src/proto/gui.pro b/src/proto/gui.pro
index 1a04248..47613f5 100644
--- a/src/proto/gui.pro
+++ b/src/proto/gui.pro
@@ -45,7 +45,6 @@
 void gui_may_update_scrollbars(void);
 void gui_update_scrollbars(int force);
 int gui_do_scroll(void);
-int gui_do_horiz_scroll(long_u leftcol, int compute_longest_lnum);
 void gui_check_colors(void);
 guicolor_T gui_get_color(char_u *name);
 int gui_get_lightness(guicolor_T pixel);
diff --git a/src/proto/mouse.pro b/src/proto/mouse.pro
index 7ce470c..e3bb5fa 100644
--- a/src/proto/mouse.pro
+++ b/src/proto/mouse.pro
@@ -14,6 +14,8 @@
 int mouse_model_popup(void);
 void reset_dragwin(void);
 int jump_to_mouse(int flags, int *inclusive, int which_button);
+int do_mousescroll_horiz(long_u leftcol);
+void do_mousescroll(int mode, cmdarg_T *cap);
 void nv_mousescroll(cmdarg_T *cap);
 void nv_mouse(cmdarg_T *cap);
 void reset_held_button(void);
diff --git a/src/proto/ui.pro b/src/proto/ui.pro
index f44bad1..7ad7c75 100644
--- a/src/proto/ui.pro
+++ b/src/proto/ui.pro
@@ -30,6 +30,8 @@
 void ui_cursor_shape(void);
 int check_col(int col);
 int check_row(int row);
+long scroll_line_len(linenr_T lnum);
+linenr_T ui_find_longest_lnum(void);
 void ui_focus_change(int in_focus);
 void im_save_status(long *psave);
 /* vim: set ft=c : */