diff --git a/types/alex/alex-tests.ts b/types/alex/alex-tests.ts
index 85055c7fff..bbf0f3253e 100644
--- a/types/alex/alex-tests.ts
+++ b/types/alex/alex-tests.ts
@@ -1,3 +1,5 @@
+import alex = require('alex');
+
 // configs
 const exemption = ['word', 'noun'];
 const deny = ['deny', 'word'];
@@ -18,15 +20,22 @@ alex('We’ve confirmed his identity.'); // $ExpectType VFile
 alex('We’ve confirmed his identity.', exemption); // $ExpectType VFile
 alex('We’ve confirmed his identity.', config); // $ExpectType VFile
 alex('We’ve confirmed his identity.', denyConfig); // $ExpectType VFile
+
 alex.markdown('### We’ve confirmed his **identity**.'); // $ExpectType VFile
 alex.markdown('### We’ve confirmed his **identity**.', exemption); // $ExpectType VFile
 alex.markdown('### We’ve confirmed his **identity**.', config); // $ExpectType VFile
 alex.markdown('### We’ve confirmed his **identity**.', denyConfig); // $ExpectType VFile
+
 alex.html('<p class="black">He walked to class.</p>'); // $ExpectType VFile
 alex.html('<p class="black">He walked to class.</p>', exemption); // $ExpectType VFile
 alex.html('<p class="black">He walked to class.</p>', config); // $ExpectType VFile
 alex.html('<p class="black">He walked to class.</p>', denyConfig); // $ExpectType VFile
+
 alex.text('The `boogeyman`.'); // $ExpectType VFile
 alex.text('The `boogeyman`.', exemption); // $ExpectType VFile
 alex.text('The `boogeyman`.', config); // $ExpectType VFile
 alex.text('The `boogeyman`.', denyConfig); // $ExpectType VFile
+
+alex.mdx('The `boogeyman`.', denyConfig); // $ExpectType VFile
+alex.mdx('<Component>He walked to class.</Component>'); // $ExpectType VFile
+alex.mdx('<Component>He walked to class.</Component>', config); // $ExpectType VFile
diff --git a/types/alex/index.d.ts b/types/alex/index.d.ts
index e9c05a42ff..9bd462819b 100644
--- a/types/alex/index.d.ts
+++ b/types/alex/index.d.ts
@@ -1,14 +1,14 @@
-// Type definitions for alex 8.2
+// Type definitions for alex 9.0
 // Project: https://alexjs.com
 // Definitions by: Piotr Błażejewicz <https://github.com/peterblazejewicz>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
-import * as vfile from 'vfile';
+import { VFile } from 'vfile';
 
 /**
  * finds gender favoring, polarizing, race related, religion inconsiderate, or other unequal phrasing in text.
  */
-declare function alex(value: vfile.VFile | string, config?: alex.Config): vfile.VFile;
+declare function alex(value: VFile | string, config?: alex.Config): VFile;
 
 declare namespace alex {
     /**
@@ -38,13 +38,21 @@ declare namespace alex {
     }
 
     /** Check Markdown (ignoring syntax). */
-    function markdown(value: vfile.VFile | string, config?: Config): vfile.VFile;
+    function markdown(value: VFile | string, config?: Config): VFile;
 
     /** Check HTML (ignoring syntax). */
-    function html(value: vfile.VFile | string, config?: Config): vfile.VFile;
+    function html(value: VFile | string, config?: Config): VFile;
 
     /** Check plain text (as in, syntax is checked). */
-    function text(value: vfile.VFile | string, config?: Config): vfile.VFile;
+    function text(value: VFile | string, config?: Config): VFile;
+
+    /**
+     * Check [MDX][] (ignoring syntax).
+     *
+     * Note: the syntax for [MDX@2][mdx-next], while currently in beta, is used in
+     * alex
+     */
+    function mdx(value: VFile | string, config?: Config): VFile;
 }
 
 export as namespace alex;
diff --git a/types/alex/package.json b/types/alex/package.json
index 421554df5b..362fa2e5ed 100644
--- a/types/alex/package.json
+++ b/types/alex/package.json
@@ -1,6 +1,6 @@
 {
     "private": true,
     "dependencies": {
-        "vfile": "^4.0.2"
+        "vfile": "^4.2.0"
     }
 }