diff --git a/Examples-(vim).md b/Examples-(vim).md
index f314c0f..9438baf 100644
--- a/Examples-(vim).md
+++ b/Examples-(vim).md
@@ -291,6 +291,7 @@ command! BTags call s:btags()
 ```
 
 ### Search lines in all open vim buffers
+(require `set hidden` to prevent vim unload buffer)
 
 ```vimL
 function! s:line_handler(l)