diff --git a/docs/.vuepress/config.js b/docs/.vuepress/config.js
index 286afaf..47a2194 100644
--- a/docs/.vuepress/config.js
+++ b/docs/.vuepress/config.js
@@ -5,7 +5,8 @@ module.exports = {
   head: [
     ['meta', {name: 'viewport', content: 'width=device-width,initial-scale=1'}]
   ],
-  theme: 'vuepress-theme-book',
+  // theme: 'vuepress-theme-book',
+  theme: 'book',
   themeConfig: {
     // logo: "/logo.png",
     searchPlaceholder: "Search...",
@@ -49,6 +50,7 @@ module.exports = {
           collapsable: false,
           children: [
             ['/people/ulf-gebhardt', 'Ulf Gebhardt'],
+            ['/people/mathias-lenz', 'Mathias Lenz'],
             // ['/random/website', 'Websites using this theme 👌'],
             // ['/random/emoji', 'Emoji 😃'],
             // ['/random/lorem', 'Lorem Ipsum 🌟']
diff --git a/docs/index.md b/docs/index.md
index b9a5d55..e0326a3 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -27,7 +27,7 @@ Since we constantly try to recruit new members this list is not complete.
 - Wolle <!--[Wolle](./people/wolfgang-huss.md))-->
 - Moriz <!--[Moriz](./people/moriz-wahl.md))-->
 - [Ulf Gebhardt](./people/ulf-gebhardt.md)
-- Mahula <!--[Mahula](./people/mathias-.md))-->
+- [Mathias Lenz](./people/mathias-lenz.md)
 - Claus-Peter <!--[Claus-Peter](./people/claus-peter-huebner.md))-->
 - Hardi <!--[Hardi](./people/chrisopher-.md))-->
 - Hannes <!--[Hannes](./people/hannes-heine.md))-->