diff --git a/autoload/fzf/vim.vim b/autoload/fzf/vim.vim
index aa27194..823f0cf 100644
--- a/autoload/fzf/vim.vim
+++ b/autoload/fzf/vim.vim
@@ -479,7 +479,8 @@ endfunction
 
 function! s:sort_buffers(...)
   let [b1, b2] = map(copy(a:000), 'get(g:fzf#vim#buffers, v:val, v:val)')
-  return b1 - b2
+  " Using minus between a float and a number in a sort function causes an error
+  return b1 > b2 ? 1 : -1
 endfunction
 
 function! fzf#vim#buffers(...)
diff --git a/plugin/fzf.vim b/plugin/fzf.vim
index 7e30bfe..f486f49 100644
--- a/plugin/fzf.vim
+++ b/plugin/fzf.vim
@@ -112,7 +112,7 @@ endif
 let g:fzf#vim#buffers = {}
 augroup fzf_buffers
   autocmd!
-  autocmd BufWinEnter,WinEnter * let g:fzf#vim#buffers[bufnr('')] = localtime()
+  autocmd BufWinEnter,WinEnter * let g:fzf#vim#buffers[bufnr('')] = reltimefloat(reltime())
   autocmd BufDelete * silent! call remove(g:fzf#vim#buffers, expand('<abuf>'))
 augroup END