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);