diff --git a/autoload/gitgutter/diff.vim b/autoload/gitgutter/diff.vim
index 1ae6d66..276b8e3 100644
--- a/autoload/gitgutter/diff.vim
+++ b/autoload/gitgutter/diff.vim
@@ -334,8 +334,9 @@ function! s:write_buffer(bufnr, file)
   if getbufvar(a:bufnr, '&fileformat') ==# 'dos'
     call map(bufcontents, 'v:val."\r"')
   endif
-  if getbufvar(a:bufnr, '&fileencoding') !=# &encoding
-    call map(bufcontents, 'iconv(v:val, &encoding, getbufvar(a:bufnr, "&fileencoding"))')
+  let fenc = getbufvar(a:bufnr, '&fileencoding')
+  if fenc !=# &encoding
+    call map(bufcontents, 'iconv(v:val, &encoding, "'.fenc.'")')
   endif
   call writefile(bufcontents, a:file)
 endfunction