diff --git a/docs/conf.py b/docs/conf.py
index e90bfab5..2e353512 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -7,8 +7,6 @@
 import os
 import sys
 
-import sphinx_rtd_theme
-
 # -- Path setup --------------------------------------------------------------
 
 # If extensions (or modules to document with autodoc) are in another directory,
@@ -54,7 +52,7 @@
 # You can specify multiple suffix as a list of string:
 #
 # source_suffix = ['.rst', '.md']
-source_suffix = ".rst"
+source_suffix = {".rst": "restructuredtext"}
 
 # The master toctree document.
 master_doc = "index"
@@ -82,12 +80,6 @@
 #
 html_theme = "sphinx_rtd_theme"
 
-# Add any paths that contain custom themes here, relative to this directory.
-# Add path to the RTD explicitly to robustify builds (otherwise might
-# fail in a clean Debian build env)
-
-html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
-
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the
 # documentation.
diff --git a/docs/requirements.txt b/docs/requirements.txt
index 0ff12812..bfbfd386 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,2 +1,2 @@
-Sphinx==5.3.0
-sphinx-rtd-theme==1.0.0
+Sphinx==8.1.3
+sphinx-rtd-theme==3.0.1