diff --git a/.github/workflows/doc.yml b/.github/workflows/doc.yml
index dad10f9..7052254 100644
--- a/.github/workflows/doc.yml
+++ b/.github/workflows/doc.yml
@@ -39,7 +39,8 @@ jobs:
           sleep 1
           # We ignore _modules since sphinx puts all modules in the module
           # overview but does not generate pages for .pyx modules.
-          linkchecker --check-extern --ignore-url=_modules/ http://localhost:8880
+          # We also ignore a url that is generated by sphinx itself (version 7.2.6).
+          linkchecker --check-extern --ignore-url='_modules/|https://www.sphinx-doc.org/' http://localhost:8880
       - uses: JamesIves/github-pages-deploy-action@3.7.1
         with:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 2a6b6dc..91bfa90 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -12,8 +12,11 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.8", "3.9", "3.10", "3.11"]
+        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
         cython: ["cython", "cython<3.0.0"]
+        exclude:
+          - python-version: 3.12
+            cython: cython<3.0.0
     steps:
       - uses: actions/checkout@v2
         with: { submodules: recursive }
@@ -22,8 +25,19 @@ jobs:
       - name: Install pplpy dependencies
         shell: bash -l {0}
         run: |
-          mamba install --quiet setuptools gmpy2 cysignals ppl "${{matrix.cython}}"
-          conda list
+          mamba install --quiet setuptools cysignals ppl gmp mpfr mpc "${{matrix.cython}}"
+      - name: Install gmpy2 via mamba
+        shell: bash -l {0}
+        if: ${{ matrix.python-version != '3.12' }}
+        run: |
+          mamba install --quiet gmpy2
+          python -c 'import gmpy2; print(gmpy2.version())'
+      - name: Install gmpy2 via pip
+        shell: bash -l {0}
+        if: ${{ matrix.python-version == '3.12' }}
+        run: |
+          pip install --pre gmpy2==2.2.0a1
+          python -c 'import gmpy2; print(gmpy2.version())'
       - name: Install pplpy
         shell: bash -l {0}
         run: |
diff --git a/README.rst b/README.rst
index 8f9ff01..e8ad7ea 100644
--- a/README.rst
+++ b/README.rst
@@ -44,7 +44,8 @@ The available objects and functions from the `ppl` Python module are:
 Installation
 ------------
 
-The project is available at `Python Package Index <https://pypi.python.org/pypi/pplpy/>`_ and
+
+The project is available at `Python Package Index <https://pypi.org/project/pplpy/>`_ and
 can be installed with pip::
 
     $ pip install pplpy
@@ -76,7 +77,7 @@ Documentation
 
 An online version of the documentation is available at https://www.sagemath.org/pplpy/
 
-Compiling the html documentation requires make and `sphinx <http://www.sphinx-doc.org/en/master/>`_.
+Compiling the html documentation requires make and `sphinx <https://www.sphinx-doc.org/en/master/>`_.
 Before building the documentation, you need to install the pplpy package (sphinx uses Python introspection).
 The documentation source code is contained in the repository `docs` where there is a standard
 Makefile with a target `html`. Running `make html` in the `docs` repository builds the documentation
@@ -96,9 +97,9 @@ Requirements
 
 - `Cython <http://cython.org>`_ (tested with both 0.29 and 3.0)
 
-- `cysignals <https://pypi.python.org/pypi/cysignals>`_
+- `cysignals <https://pypi.org/project/cysignals/>`_
 
-- `gmpy2 <https://pypi.python.org/pypi/gmpy2>`_
+- `gmpy2 <https://pypi.org/project/gmpy2/>`_
 
 On Debian/Ubuntu systems the dependencies can be installed with::
 
diff --git a/docs/source/index.rst b/docs/source/index.rst
index 2e4ad93..f55d874 100644
--- a/docs/source/index.rst
+++ b/docs/source/index.rst
@@ -6,7 +6,7 @@ Welcome to pplpy's documentation!
 Installation
 ------------
 
-pplpy is available from the `Python Package Index <https://pypi.python.org/pypi/pplpy/>`_. You can hence install it with::
+pplpy is available from the `Python Package Index <https://pypi.org/project/pplpy/>`_. You can hence install it with::
 
     $ pip install pplpy
 
diff --git a/environment.test.yml b/environment.test.yml
index bc8aba6..0fba3b2 100644
--- a/environment.test.yml
+++ b/environment.test.yml
@@ -4,6 +4,7 @@ channels:
   - defaults
 dependencies:
   - sphinx
+  - pip
   - pip:
     - linkchecker
     - cython-lint 
diff --git a/setup.cfg b/setup.cfg
index 23c2dc8..10092be 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -20,6 +20,7 @@ classifiers =
     Programming Language :: Python :: 3.9
     Programming Language :: Python :: 3.10
     Programming Language :: Python :: 3.11
+    Programming Language :: Python :: 3.12
 keywords =
     polyhedron
     polytope