diff --git a/index.js b/index.js
index 61670aa..ccd80ec 100755
--- a/index.js
+++ b/index.js
@@ -5,6 +5,7 @@ import {createUnifiedLanguageServer} from 'unified-language-server'
 process.title = 'remark-language-server'
 
 createUnifiedLanguageServer({
+  configurationSection: 'remark',
   ignoreName: '.remarkignore',
   packageField: 'remarkConfig',
   pluginPrefix: 'remark',
diff --git a/package.json b/package.json
index 0bb4b1e..8d26973 100644
--- a/package.json
+++ b/package.json
@@ -29,7 +29,7 @@
     "index.js"
   ],
   "dependencies": {
-    "unified-language-server": "^3.0.0"
+    "unified-language-server": "^4.0.0"
   },
   "devDependencies": {
     "prettier": "^3.0.0",
diff --git a/readme.md b/readme.md
index 511e29b..9ad35b3 100644
--- a/readme.md
+++ b/readme.md
@@ -14,6 +14,8 @@ A language server to lint and format markdown files with **[remark][]**.
 *   [When should I use this?](#when-should-i-use-this)
 *   [Install](#install)
 *   [Use](#use)
+    *   [Configuration file](#configuration-file)
+    *   [Settings](#settings)
 *   [Examples](#examples)
     *   [Emacs](#emacs)
     *   [Neovim](#neovim)
@@ -51,6 +53,8 @@ Because this is based on
 [`unified-languageserver-node`][unified-languageserver-node], the same features
 are supported.
 
+### Configuration file
+
 `remark-language-server` uses the same configuration files as
 [`remark-cli`][remark-cli].
 These files are:
@@ -68,6 +72,13 @@ Language clients should notify the language server if these files change.
 They are looked up starting at the folder where the checked markdown file
 exists.
 
+### Settings
+
+This language server supports the following settings:
+
+*   `remark.requireConfig` (`boolean`, default: `false`) — If true, only perform
+    actions if a [configuration file][configuration-file] is found.
+
 ## Examples
 
 ### Emacs
@@ -82,7 +93,11 @@ client.
 This means you can add remark language server in one line:
 
 ```lua
-require'lspconfig'.remark_ls.setup{}
+require'lspconfig'.remark_ls.setup {
+  settings = {
+    requireConfig = true
+  }
+}
 ```
 
 `nvim-lspconfig` has
@@ -100,6 +115,10 @@ if (executable('remark-language-server'))
   \ 'name': 'remark',
   \ 'cmd': {server_info->['remark-language-server', '--stdio']},
   \ 'allowlist': ['markdown'],
+  \ 'config': lsp_settings#get('remark-language-server', 'config', lsp_settings#server_config('remark-language-server')),
+  \ 'workspace_config': lsp_settings#get('remark-language-server', 'workspace_config', {
+  \   'requireConfig': v:true,
+  \ }),
   \ })
 endif
 ```
@@ -140,6 +159,8 @@ abide by its terms.
 
 [build]: https://github.com/remarkjs/remark-language-server/actions
 
+[configuration-file]: #configuration-file
+
 [downloads-badge]: https://img.shields.io/npm/dm/remark-language-server.svg
 
 [downloads]: https://www.npmjs.com/package/remark-language-server