diff --git a/README.md b/README.md
index 53829fe..8ddfbbb 100644
--- a/README.md
+++ b/README.md
@@ -57,3 +57,15 @@ This plugin provides some plugins integration.
 #### [vim-compete](https://github.com/hrsh7th/vim-compete)
 - Snippet completion.
 
+
+# FAQ
+
+#### How to prevent snippet expansion unexpectedly?
+You can use `vsnip_integ#skip_complete_done('<C-y>')`
+
+For example, the following mapping makes to prevent snippet expansion when you press `<C-y>` explicitly.
+
+```viml
+inoremap <expr> <C-y> vsnip_integ#skip_complete_done('<C-y>')
+```
+
diff --git a/autoload/vsnip_integ.vim b/autoload/vsnip_integ.vim
index 5e3f66a..268ad97 100644
--- a/autoload/vsnip_integ.vim
+++ b/autoload/vsnip_integ.vim
@@ -1,6 +1,6 @@
 let s:TextEdit = vital#vsnip#import('VS.LSP.TextEdit')
 
-let s:stop = v:false
+let s:skip = v:false
 
 "
 " CompleteDone context.
@@ -18,15 +18,24 @@ let s:context = {
 
 inoremap <silent> <Plug>(vsnip_integ:on_complete_done_after) <C-r>=<SID>on_complete_done_after()<CR>
 
+"
+" vsnip_integ#skip_complete_done
+"
+function! vsnip_integ#skip_complete_done(...) abort
+  let s:skip = v:true
+  call timer_start(0, { -> execute('let s:skip = v:false') })
+  return get(a:000, 0, '')
+endfunction
+
 "
 " vsnip_integ#on_complete_done_for_lsp
 "
 " Deprecated.
 "
 function! vsnip_integ#on_complete_done_for_lsp(context) abort
-  if s:stop | return | endif
-  let s:stop = v:true
-  call timer_start(0, { -> execute('let s:stop = v:false') })
+  if s:skip | return | endif
+  let s:skip = v:true
+  call timer_start(0, { -> execute('let s:skip = v:false') })
 
   let s:context = {
   \   'done_line': getline('.'),
@@ -42,9 +51,9 @@ endfunction
 " vsnip_integ#on_complete_done
 "
 function! vsnip_integ#on_complete_done(completed_item) abort
-  if s:stop | return | endif
-  let s:stop = v:true
-  call timer_start(0, { -> execute('let s:stop = v:false') })
+  if s:skip | return | endif
+  let s:skip = v:true
+  call timer_start(0, { -> execute('let s:skip = v:false') })
 
   let l:context = s:extract_user_data(a:completed_item)
   if !empty(l:context)
diff --git a/plugin/vsnip_integ.vim b/plugin/vsnip_integ.vim
index 80e503d..701580c 100644
--- a/plugin/vsnip_integ.vim
+++ b/plugin/vsnip_integ.vim
@@ -11,3 +11,5 @@ augroup vsnip_integ
   autocmd VimEnter * call vsnip_integ#integration#attach()
 augroup END
 
+inoremap <silent> <Plug>(vsnip_integ_skip_complete_done) <C-r>=vsnip_integ#skip_complete_done()<CR>
+