diff --git a/src/proto/undo.pro b/src/proto/undo.pro
index e712f03..e5f28be 100644
--- a/src/proto/undo.pro
+++ b/src/proto/undo.pro
@@ -5,6 +5,9 @@
 int u_inssub __ARGS((linenr_T lnum));
 int u_savedel __ARGS((linenr_T lnum, long nlines));
 int undo_allowed __ARGS((void));
+void u_compute_hash __ARGS((char_u *hash));
+void u_read_undo __ARGS((char_u *name, char_u *hash));
+void u_write_undo __ARGS((char_u *name, int forceit, buf_T *buf, char_u *hash));
 void u_undo __ARGS((int count));
 void u_redo __ARGS((int count));
 void undo_time __ARGS((long step, int sec, int absolute));