diff --git a/.github/workflows/python-pull-request.yml b/.github/workflows/python-pull-request.yml
index cb9fc0a..aa4b03c 100644
--- a/.github/workflows/python-pull-request.yml
+++ b/.github/workflows/python-pull-request.yml
@@ -19,7 +19,7 @@ jobs:
   checks:
     strategy:
       matrix:
-        python-version: ["3.11", "3.12"]
+        python-version: ["3.11", "3.12", "3.13"]
     uses: ecmwf/reusable-workflows/.github/workflows/qa-pytest-pyproject.yml@v2
     with:
       python-version: ${{ matrix.python-version }}
diff --git a/pyproject.toml b/pyproject.toml
index ca8e72c..9507e13 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -21,7 +21,7 @@ authors = [
   { name = "European Centre for Medium-Range Weather Forecasts (ECMWF)", email = "software.support@ecmwf.int" },
 ]
 
-requires-python = ">=3.11"
+requires-python = ">=3.11,<3.14"
 
 classifiers = [
   "Development Status :: 4 - Beta",
@@ -31,6 +31,7 @@ classifiers = [
   "Programming Language :: Python :: 3 :: Only",
   "Programming Language :: Python :: 3.11",
   "Programming Language :: Python :: 3.12",
+  "Programming Language :: Python :: 3.13",
   "Programming Language :: Python :: Implementation :: CPython",
   "Programming Language :: Python :: Implementation :: PyPy",
 ]