diff --git a/src/proto/undo.pro b/src/proto/undo.pro
new file mode 100644
index 0000000..8ac2323
--- /dev/null
+++ b/src/proto/undo.pro
@@ -0,0 +1,18 @@
+/* undo.c */
+int u_save_cursor __ARGS((void));
+int u_save __ARGS((linenr_T top, linenr_T bot));
+int u_savesub __ARGS((linenr_T lnum));
+int u_inssub __ARGS((linenr_T lnum));
+int u_savedel __ARGS((linenr_T lnum, long nlines));
+void u_undo __ARGS((int count));
+void u_redo __ARGS((int count));
+void u_sync __ARGS((void));
+void u_unchanged __ARGS((buf_T *buf));
+void u_clearall __ARGS((buf_T *buf));
+void u_saveline __ARGS((linenr_T lnum));
+void u_clearline __ARGS((void));
+void u_undoline __ARGS((void));
+void u_blockfree __ARGS((buf_T *buf));
+int bufIsChanged __ARGS((buf_T *buf));
+int curbufIsChanged __ARGS((void));
+/* vim: set ft=c : */