diff --git a/autoload/sy.vim b/autoload/sy.vim
index c3e1962..756397d 100644
--- a/autoload/sy.vim
+++ b/autoload/sy.vim
@@ -96,7 +96,8 @@ endfunction
 
 " Function: #stop {{{1
 function! sy#stop(bnum) abort
-  if !exists('b:sy')
+  let bvars = getbufvar(a:bnum, '')
+  if empty(bvars) || !has_key(bvars, 'sy')
     return
   endif
 
diff --git a/autoload/sy/sign.vim b/autoload/sy/sign.vim
index 0815c64..07412c4 100644
--- a/autoload/sy/sign.vim
+++ b/autoload/sy/sign.vim
@@ -42,16 +42,18 @@ endfunction
 
 " Function: #remove_all {{{1
 function! sy#sign#remove_all(bnum) abort
+  let sy = getbufvar(a:bnum, 'sy')
+
   if g:signify_sign_overwrite
-    execute 'sign unplace * buffer='. b:sy.buffer
+    execute 'sign unplace * buffer='. sy.buffer
   else
-    for hunk in b:sy.hunks
+    for hunk in sy.hunks
       for id in hunk.ids
         execute 'sign unplace' id
       endfor
     endfor
   endif
 
-  let b:sy.hunks = []
-  let b:sy.stats = [0, 0, 0]
+  let sy.hunks = []
+  let sy.stats = [0, 0, 0]
 endfunction
diff --git a/plugin/signify.vim b/plugin/signify.vim
index 2d80ab0..a0d13e3 100644
--- a/plugin/signify.vim
+++ b/plugin/signify.vim
@@ -14,8 +14,7 @@ augroup signify
   autocmd VimEnter             * call sy#highlight#setup()
   autocmd BufRead,BufEnter     * let b:sy_path = resolve(expand('<afile>:p'))
   autocmd BufRead,BufWritePost * call sy#start(b:sy_path)
-
-  autocmd BufDelete * call sy#stop(expand('<abuf>'))
+  autocmd BufDelete            * call sy#stop(expand('<abuf>'))
 
   if get(g:, 'signify_update_on_bufenter')
     autocmd BufEnter * nested