diff --git a/.github/workflows/deploy_release.yml b/.github/workflows/deploy_release.yml
index 8fe931763c..adcfd88d41 100644
--- a/.github/workflows/deploy_release.yml
+++ b/.github/workflows/deploy_release.yml
@@ -29,6 +29,11 @@ jobs:
 
     - run: echo "AMICI_DIR=$(pwd)" >> $GITHUB_ENV
 
+    - name: Remove direct dependencies from setup.cfg
+      # Remove any "git+https"-based dependencies that are not supported
+      #  by PyPI and are only required for testing.
+      run: sed -i '/git+https/d' python/sdist/setup.cfg
+
     - name: sdist
       run: scripts/buildSdist.sh
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 513cf82efc..1fa8153e35 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## v0.X Series
 
+### v0.21.1 (2024-01-17)
+
+Fixed package configuration for PyPI upload. No further changes.
+
 ### v0.21.0 (2024-01-16)
 
 **Deprecations**
diff --git a/python/sdist/setup.cfg b/python/sdist/setup.cfg
index bf0e61cdd5..cc82ef08de 100644
--- a/python/sdist/setup.cfg
+++ b/python/sdist/setup.cfg
@@ -43,6 +43,9 @@ include_package_data = True
 zip_safe = False
 
 [options.extras_require]
+# Don't include any URLs here - they are not supported by PyPI:
+#  HTTPError: 400 Bad Request from https://upload.pypi.org/legacy/
+#  Invalid value for requires_dist. Error: Can't have direct dependency: ...
 petab = petab>=0.2.1
 pysb = pysb>=1.13.1
 test =
diff --git a/version.txt b/version.txt
index 885415662f..a67cebaf7f 100644
--- a/version.txt
+++ b/version.txt
@@ -1 +1 @@
-0.21.0
+0.21.1