diff --git a/docs/source/conf.py b/docs/source/conf.py
index a19993e..82a0af8 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -64,8 +64,7 @@
     'use_fullscreen_button': False,
     'path_to_docs': 'docs',
     'use_edit_page_button': True,
-    'extra_navbar': '',
-    'extra_navbar': '<p>Made possible by the support of <a href="http://nccr-marvel.ch/" target="_blank"> NCCR MARVEL</a>, <a href="http://www.max-centre.eu/" target="_blank"> MaX CoE</a> and the <a href="https://www.materialscloud.org/swissuniversities" target="_blank"> swissuniversities P-5 project</a>.</p>'
+    'extra_footer': '<p>Made possible by the support of <a href="http://nccr-marvel.ch/" target="_blank"> NCCR MARVEL</a>, <a href="http://www.max-centre.eu/" target="_blank"> MaX CoE</a> and the <a href="https://www.materialscloud.org/swissuniversities" target="_blank"> swissuniversities P-5 project</a>.</p>'
 }
 html_domain_indices = True
 html_logo = '_static/logo.png'
diff --git a/pyproject.toml b/pyproject.toml
index 8db91a3..a940a3e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -36,10 +36,10 @@ Documentation = 'https://aiida-pseudo.readthedocs.io'
 
 [project.optional-dependencies]
 docs = [
-    'sphinx~=4.1',
+    'sphinx~=6.0',
     'sphinx-copybutton~=0.5.0',
-    'sphinx-book-theme~=0.3.2',
-    'sphinx-autoapi~=1.8.1',
+    'sphinx-book-theme~=1.0',
+    'sphinx-autoapi~=3.0',
     'sphinx-click~=4.0',
 ]
 pre-commit = [