diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 7201fac..cf58c6b 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -8,7 +8,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest]
-        python-version: ["3.8", "3.10", "3.11"]
+        python-version: ["3.8", "3.9", "3.10", "3.11"]
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/setup-python@v4
diff --git a/pyproject.toml b/pyproject.toml
index 8467130..8b9ae27 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -9,7 +9,7 @@ keywords = ["vmcon", "optimisation", "non-linear constrained optimisation"]
 readme = "README.md"
 license = { file = "LICENSE" }
 authors = [{ name = "Timothy Nunn", email = "timothy.nunn@ukaea.uk" }]
-requires-python = ">=3.6"
+requires-python = ">=3.8"
 dependencies = ["numpy>=1.19", "cvxpy>=1.3"]
 classifiers = [
     "Intended Audience :: Science/Research",