diff --git a/plugin/CSApprox.vim b/plugin/CSApprox.vim
index 1ed5a3d..7698aff 100644
--- a/plugin/CSApprox.vim
+++ b/plugin/CSApprox.vim
@@ -771,10 +771,10 @@ function! s:CSApproxSnapshot(file, overwrite)
     let lines += [ 'endif' ]
     let lines += [ '' ]
     let lines += [ 'if v:version < 700' ]
-    let lines += [ '    let g:colors_name = ' . string(fnamemodify(file, ':t:r')) ]
+    let lines += [ '    let g:colors_name = expand("<sfile>:t:r")' ]
     let lines += [ '    command! -nargs=+ CSAHi exe "hi" substitute(substitute(<q-args>, "undercurl", "underline", "g"), "guisp\\S\\+", "", "g")' ]
     let lines += [ 'else' ]
-    let lines += [ '    let g:colors_name = ' . string(fnamemodify(file, ':t:r')) ]
+    let lines += [ '    let g:colors_name = expand("<sfile>:t:r")' ]
     let lines += [ '    command! -nargs=+ CSAHi exe "hi" <q-args>' ]
     let lines += [ 'endif' ]
     let lines += [ '' ]