diff --git a/.github/workflows/pythonpackage.yml b/.github/workflows/pythonpackage.yml
index fd73d6d..c08f5b5 100644
--- a/.github/workflows/pythonpackage.yml
+++ b/.github/workflows/pythonpackage.yml
@@ -5,21 +5,28 @@ name: Python package
 
 on: [push, pull_request, workflow_dispatch]
 
+permissions:
+  contents: read
+
 jobs:
   build:
-
-    runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12", "3.13", "3.13t"]
         include:
         - experimental: false
+        - os: ubuntu-latest
+        - python-version: "3.7"
+          os: ubuntu-22.04
+
+    runs-on: ${{ matrix.os }}
+
     continue-on-error: ${{ matrix.experimental }}
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@v6
       with:
         python-version: ${{ matrix.python-version }}
         allow-prereleases: ${{ matrix.experimental }}
diff --git a/SECURITY.md b/SECURITY.md
new file mode 100644
index 0000000..9e0c0d1
--- /dev/null
+++ b/SECURITY.md
@@ -0,0 +1,3 @@
+# Security Policy
+
+See [GitPython](https://github.com/gitpython-developers/GitPython/blob/main/SECURITY.md). Vulnerabilities found in `smmap` can be reported there.
diff --git a/doc/source/changes.rst b/doc/source/changes.rst
index dc243eb..faed608 100644
--- a/doc/source/changes.rst
+++ b/doc/source/changes.rst
@@ -2,6 +2,14 @@
 Changelog
 #########
 
+******
+v5.0.3
+******
+
+- declare support for Python 3.13
+
+For more, see https://github.com/gitpython-developers/smmap/compare/v5.0.3...v5.0.2
+
 ******
 v5.0.2
 ******
diff --git a/setup.py b/setup.py
index d7e1842..7deb178 100755
--- a/setup.py
+++ b/setup.py
@@ -44,6 +44,7 @@
         "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: 3.11",
         "Programming Language :: Python :: 3.12",
+        "Programming Language :: Python :: 3.13",
         "Programming Language :: Python :: 3 :: Only",
     ],
     long_description=long_description,
diff --git a/smmap/__init__.py b/smmap/__init__.py
index 657c8c5..6231810 100644
--- a/smmap/__init__.py
+++ b/smmap/__init__.py
@@ -3,7 +3,7 @@
 __author__ = "Sebastian Thiel"
 __contact__ = "byronimo@gmail.com"
 __homepage__ = "https://github.com/gitpython-developers/smmap"
-version_info = (5, 0, 2)
+version_info = (5, 0, 3)
 __version__ = '.'.join(str(i) for i in version_info)
 
 # make everything available in root package for convenience