diff --git a/README-maintainer b/README-maintainer
index 8306d9af..f161df46 100644
--- a/README-maintainer
+++ b/README-maintainer
@@ -31,6 +31,13 @@ Memory checks:
    --enable-werror --disable-shared
 
 
+CHECKING DOCS ON readthedocs
+
+To check docs on readthedocs.io without running all of CI, push to the
+doc-check branch. Then visit https://qpdf.readthedocs.io/en/doc-check/
+Building docs from pull requests is also enabled.
+
+
 GOOGLE OSS-FUZZ
 
 * See ../misc/fuzz (not in repo) for unfixed, downloaded fuzz test cases
diff --git a/appimage/Dockerfile b/appimage/Dockerfile
index 51221908..0b7232f9 100644
--- a/appimage/Dockerfile
+++ b/appimage/Dockerfile
@@ -7,7 +7,7 @@ RUN apt-get update && \
        inkscape imagemagick busybox-static wget fuse && \
     apt-get clean && \
     rm -rf /var/lib/apt/lists/*
-RUN pip3 install sphinx
+RUN pip3 install sphinx sphinx_rtd_theme
 COPY entrypoint /entrypoint
 RUN chmod +x /entrypoint
 ENTRYPOINT [ "/entrypoint" ]
diff --git a/build-scripts/build-linux b/build-scripts/build-linux
index 1e20a224..bb5baf36 100755
--- a/build-scripts/build-linux
+++ b/build-scripts/build-linux
@@ -5,7 +5,7 @@ sudo apt-get -y install \
    autoconf build-essential zlib1g-dev libjpeg-dev libgnutls28-dev \
    libssl-dev python3-pip texlive-latex-extra latexmk \
    inkscape imagemagick libtiff-tools ghostscript
-pip3 install sphinx
+pip3 install sphinx sphinx_rtd_theme
 ./configure --enable-werror --enable-doc-maintenance \
     --enable-crypto-native --enable-crypto-openssl --enable-crypto-gnutls \
     --enable-show-failed-test-output --enable-test-compare-images
diff --git a/build-scripts/prebuild b/build-scripts/prebuild
index f8d1f61b..76f9bf6d 100755
--- a/build-scripts/prebuild
+++ b/build-scripts/prebuild
@@ -5,7 +5,7 @@ sudo apt-get update
 sudo apt-get -y install \
    autoconf build-essential zlib1g-dev libjpeg-dev \
    python3-pip texlive-latex-extra latexmk inkscape imagemagick
-pip3 install sphinx
+pip3 install sphinx sphinx_rtd_theme
 ./configure --enable-doc-maintenance
 make -j$(nproc) build_manual
 zip -r doc.zip doc/*html doc/*.pdf
diff --git a/manual/conf.py b/manual/conf.py
index 7dde20ca..aaed236f 100644
--- a/manual/conf.py
+++ b/manual/conf.py
@@ -6,14 +6,19 @@
 #
 # To see the default sample conf.py, run sphinx-quickstart in an empty
 # directory. Most of the original comments and options were removed.
+import sphinx_rtd_theme  # noQA F401
 
 project = 'QPDF'
 copyright = '2005-2021, Jay Berkenbilt'
 author = 'Jay Berkenbilt'
 release = '10.4.0'
 version = release
-html_theme = 'nature'
+extensions = [
+    'sphinx_rtd_theme',
+]
+html_theme = 'sphinx_rtd_theme'
 html_theme_options = {
     "body_max_width": None,
 }
+html_logo = '../logo/qpdf.svg'
 highlight_language = 'none'
diff --git a/manual/installation.rst b/manual/installation.rst
index 568c2e20..197977e7 100644
--- a/manual/installation.rst
+++ b/manual/installation.rst
@@ -63,10 +63,11 @@ ghostscript.
 Pre-built documentation is distributed with qpdf, so you should
 generally not need to rebuild the documentation. In order to build the
 documentation from source, you need to install `Sphinx
-<https://sphinx-doc.org>`__. To build the PDF version of the
-documentation, you need ``pdflatex``, ``latexmk``, and a fairly complete
-LaTeX installation. Detailed requirements can be found in the Sphinx
-documentation.
+<https://sphinx-doc.org>`__ along with the ``sphinx_rtd_doc`` theme
+(``pip install sphinx sphinx_rtd_theme``). To build the PDF version of
+the documentation, you need ``pdflatex``, ``latexmk``, and a fairly
+complete LaTeX installation. Detailed requirements can be found in the
+Sphinx documentation.
 
 .. _building: