diff --git a/src/proto/os_unix.pro b/src/proto/os_unix.pro
index 735565a..36193bb 100644
--- a/src/proto/os_unix.pro
+++ b/src/proto/os_unix.pro
@@ -19,6 +19,7 @@
 void mch_settitle __ARGS((char_u *title, char_u *icon));
 void mch_restore_title __ARGS((int which));
 int vim_is_xterm __ARGS((char_u *name));
+int use_xterm_like_mouse __ARGS((char_u *name));
 int use_xterm_mouse __ARGS((void));
 int vim_is_iris __ARGS((char_u *name));
 int vim_is_vt300 __ARGS((char_u *name));