diff --git a/src/vim.h b/src/vim.h
index 1c91b7d..43dbd8c 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -1898,6 +1898,7 @@
 # define CURSOR_MOVED		0x100
 # define MOUSE_FOLD_CLOSE	0x200	/* clicked on '-' in fold column */
 # define MOUSE_FOLD_OPEN	0x400	/* clicked on '+' in fold column */
+# define MOUSE_WINBAR		0x800	/* in window toolbar */
 
 /* flags for jump_to_mouse() */
 # define MOUSE_FOCUS		0x01	/* need to stay in this window */