diff --git a/.github/workflows/pull-request-create-release.yml b/.github/workflows/pull-request-create-release.yml
index e2886057b..9a54cdfeb 100644
--- a/.github/workflows/pull-request-create-release.yml
+++ b/.github/workflows/pull-request-create-release.yml
@@ -38,11 +38,11 @@ jobs:
           - name: macOS
             os: macos-latest
             dist_name: betty-macos
-            python: '3.12'
+            python: '3.13'
           - name: Windows
             os: windows-2019
             dist_name: betty-windows
-            python: '3.12'
+            python: '3.13'
     steps:
       - name: Check out the source code
         uses: actions/checkout@v4
diff --git a/.github/workflows/release-build-pyinstaller.yml b/.github/workflows/release-build-pyinstaller.yml
index 4dc17a1ea..9d24ba769 100644
--- a/.github/workflows/release-build-pyinstaller.yml
+++ b/.github/workflows/release-build-pyinstaller.yml
@@ -14,11 +14,11 @@ jobs:
           - name: macOS
             os: macos-latest
             dist_name: betty-macos
-            python: '3.12'
+            python: '3.13'
           - name: Windows
             os: windows-2019
             dist_name: betty-windows
-            python: '3.12'
+            python: '3.13'
     steps:
       - name: Check out the source code
         uses: actions/checkout@v4
diff --git a/.github/workflows/release-build-setuptools.yml b/.github/workflows/release-build-setuptools.yml
index 9c3ea9d87..f6c6ef4d3 100644
--- a/.github/workflows/release-build-setuptools.yml
+++ b/.github/workflows/release-build-setuptools.yml
@@ -11,9 +11,9 @@ jobs:
     strategy:
       matrix:
         include:
-          - name: 'Python 3.12'
+          - name: 'Python 3.13'
             os: ubuntu-latest
-            python: '3.12'
+            python: '3.13'
     steps:
       - name: Check out the source code
         uses: actions/checkout@v4
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 360272ec3..782d8ed6d 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -18,6 +18,9 @@ jobs:
         include:
           # The number of builds that submit code coverage configured here MUST be identical
           # to the number of `after_n_builds` in /home/bart/code/bartfeenstra/betty/codecov.yml.
+          - name: 'Python 3.13'
+            os: ubuntu-latest
+            python: '3.13'
           - name: 'Python 3.12'
             os: ubuntu-latest
             python: '3.12'
@@ -26,10 +29,10 @@ jobs:
             python: '3.11'
           - name: 'macOS'
             os: macos-latest
-            python: '3.12'
+            python: '3.13'
           - name: 'Windows'
             os: windows-latest
-            python: '3.12'
+            python: '3.13'
     timeout-minutes: 60
     steps:
       - name: Check out the source code
diff --git a/betty/tests/coverage/test_coverage.py b/betty/tests/coverage/test_coverage.py
index 48b97055b..1a9f23770 100644
--- a/betty/tests/coverage/test_coverage.py
+++ b/betty/tests/coverage/test_coverage.py
@@ -307,6 +307,8 @@ class TestKnownToBeMissing:
         "FetchResponse": {
             # This is inherited from @dataclass.
             "__eq__": TestKnownToBeMissing,
+            # This is inherited from @dataclass.
+            "__replace__": TestKnownToBeMissing,
         },
     },
     "betty/fs.py": {
diff --git a/codecov.yml b/codecov.yml
index 063f3461e..4bb6e9e7a 100644
--- a/codecov.yml
+++ b/codecov.yml
@@ -3,4 +3,4 @@ codecov:
     # The number of builds configured here MUST be identical to the number
     # of matrix options in /.github/workflows/test.yml that submit code coverage
     # reports to Codecov.io.
-    after_n_builds: 4
+    after_n_builds: 5
diff --git a/pyproject.toml b/pyproject.toml
index 1c9024fb1..cd25c469c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -49,10 +49,10 @@ classifiers = [
     'Intended Audience :: Science/Research',
     'License :: OSI Approved :: GNU General Public License v3 or later (GPLv3+)',
     'Programming Language :: JavaScript',
+    'Programming Language :: Lua',
     'Programming Language :: Python :: 3.11',
     'Programming Language :: Python :: 3.12',
-    'Programming Language :: Lua',
-    'Programming Language :: JavaScript',
+    'Programming Language :: Python :: 3.13',
     'Programming Language :: Unix Shell',
     'Operating System :: MacOS :: MacOS X',
     'Operating System :: POSIX :: Linux',