diff --git a/docs/vim.md b/docs/vim.md
index 70eb9efdf783..ed9edb6d7223 100644
--- a/docs/vim.md
+++ b/docs/vim.md
@@ -116,7 +116,7 @@ Update your `coc-settings.json` for languages that you want format on save.
 
 ```json
 {
-  "coc.preferences.formatOnSaveFiletypes": ["css", "Markdown"]
+  "coc.preferences.formatOnSaveFiletypes": ["css", "markdown"]
 }
 ```