diff --git a/docs/INSTALL.rst b/docs/INSTALL.rst
index b2a5a09..22e20d4 100644
--- a/docs/INSTALL.rst
+++ b/docs/INSTALL.rst
@@ -12,7 +12,7 @@
 
 - doxygen
 - graphviz
-- sphinx >= 4.0
+- sphinx
 - sphinxcontrib-doxylink
 
 Build
diff --git a/docs/conf.py b/docs/conf.py
index d1a6386..5fcfc13 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -10,7 +10,7 @@
 # https://www.sphinx-doc.org/en/master/usage/configuration.html#project-information
 
 project = 'NDNS: Domain Name Service for Named Data Networking'
-copyright = 'Copyright © 2014-2023 Named Data Networking Project.'
+copyright = 'Copyright © 2014-2025 Named Data Networking Project.'
 author = 'Named Data Networking Project'
 
 # The short X.Y version.
diff --git a/docs/doxygen.conf.in b/docs/doxygen.conf.in
index 78e40a2..f8fa0c3 100644
--- a/docs/doxygen.conf.in
+++ b/docs/doxygen.conf.in
@@ -1143,15 +1143,6 @@
 
 HTML_COLORSTYLE_GAMMA  = 91
 
-# If the HTML_TIMESTAMP tag is set to YES then the footer of each generated HTML
-# page will contain the date and time when the page was generated. Setting this
-# to YES can help to show when doxygen was last run and thus if the
-# documentation is up to date.
-# The default value is: NO.
-# This tag requires that the tag GENERATE_HTML is set to YES.
-
-HTML_TIMESTAMP         = NO
-
 # If the HTML_DYNAMIC_SECTIONS tag is set to YES then the generated HTML
 # documentation will contain sections that can be hidden and shown after the
 # page has loaded.
@@ -1422,17 +1413,6 @@
 
 FORMULA_FONTSIZE       = 10
 
-# Use the FORMULA_TRANPARENT tag to determine whether or not the images
-# generated for formulas are transparent PNGs. Transparent PNGs are not
-# supported properly for IE 6.0, but are supported on all modern browsers.
-#
-# Note that when changing this option you need to delete any form_*.png files in
-# the HTML output directory before the changes have effect.
-# The default value is: YES.
-# This tag requires that the tag GENERATE_HTML is set to YES.
-
-FORMULA_TRANSPARENT    = YES
-
 # Enable the USE_MATHJAX option to render LaTeX formulas using MathJax (see
 # http://www.mathjax.org) which uses client side Javascript for the rendering
 # instead of using pre-rendered bitmaps. Use this if you do not have LaTeX
@@ -1719,14 +1699,6 @@
 
 LATEX_BIB_STYLE        = plain
 
-# If the LATEX_TIMESTAMP tag is set to YES then the footer of each generated
-# page will contain the date and time when the page was generated. Setting this
-# to NO can help when comparing the output of multiple runs.
-# The default value is: NO.
-# This tag requires that the tag GENERATE_LATEX is set to YES.
-
-LATEX_TIMESTAMP        = NO
-
 #---------------------------------------------------------------------------
 # Configuration options related to the RTF output
 #---------------------------------------------------------------------------
@@ -2057,15 +2029,6 @@
 # Configuration options related to the dot tool
 #---------------------------------------------------------------------------
 
-# If the CLASS_DIAGRAMS tag is set to YES, doxygen will generate a class diagram
-# (in HTML and LaTeX) for classes with base or super classes. Setting the tag to
-# NO turns the diagrams off. Note that this option also works with HAVE_DOT
-# disabled, but it is recommended to install and use dot, since it yields more
-# powerful graphs.
-# The default value is: YES.
-
-CLASS_DIAGRAMS         = YES
-
 # You can include diagrams made with dia in doxygen documentation. Doxygen will
 # then run dia to produce the diagram and insert it in the documentation. The
 # DIA_PATH tag allows you to specify the directory where the dia binary resides.
@@ -2098,23 +2061,6 @@
 
 DOT_NUM_THREADS        = 0
 
-# When you want a differently looking font in the dot files that doxygen
-# generates you can specify the font name using DOT_FONTNAME. You need to make
-# sure dot is able to find the font, which can be done by putting it in a
-# standard location or by setting the DOTFONTPATH environment variable or by
-# setting DOT_FONTPATH to the directory containing the font.
-# The default value is: Helvetica.
-# This tag requires that the tag HAVE_DOT is set to YES.
-
-DOT_FONTNAME           = Helvetica
-
-# The DOT_FONTSIZE tag can be used to set the size (in points) of the font of
-# dot graphs.
-# Minimum value: 4, maximum value: 24, default value: 10.
-# This tag requires that the tag HAVE_DOT is set to YES.
-
-DOT_FONTSIZE           = 10
-
 # By default doxygen will tell dot to use the default font as specified with
 # DOT_FONTNAME. If you specify a different font using DOT_FONTNAME you can set
 # the path where dot can find it using this tag.
diff --git a/docs/requirements.txt b/docs/requirements.txt
new file mode 100644
index 0000000..1348feb
--- /dev/null
+++ b/docs/requirements.txt
@@ -0,0 +1,3 @@
+docutils>=0.20
+sphinx>=7.0.1,<9
+sphinxcontrib-doxylink~=1.13