diff --git a/.gitea/workflows/build-and-publish.yaml b/.gitea/workflows/build-and-publish.yaml
index ca17cbd..7df7ba8 100644
--- a/.gitea/workflows/build-and-publish.yaml
+++ b/.gitea/workflows/build-and-publish.yaml
@@ -46,10 +46,19 @@ jobs:
           python-version: 3.12
 
       - name: Install test dependencies
-        run: python -m pip install --upgrade pip && pip install -r requirements.txt
+        run: python -m pip install --upgrade pip && pip install -r requirements-dev.txt
+
+      - name: Cache pip dependencies
+        uses: actions/cache@v4
+        with:
+          path: ~/.cache/pip
+          key: "$RUNNER_OS-pip-${{ hashFiles('requirements-dev.txt') }}"
+          restore-keys: |
+            $RUNNER_OS-pip-
 
       - name: Run unit tests
-        run: pytest -q
+        run: python -m pytest -q
+
       - name: Determine registry host
         run: echo "REGISTRY=${GITHUB_SERVER_URL#*://}" >> "$GITHUB_ENV"
 
diff --git a/README.md b/README.md
index 0a89b3e..4ad7a25 100644
--- a/README.md
+++ b/README.md
@@ -50,11 +50,13 @@ docker run --rm -p 110:110 -p 25:25 \
 
 ## Tests
 
-Run tests locally with:
+Install development dependencies and run the test suite:
 
 ```bash
+python -m venv .venv
+source .venv/bin/activate
 python -m pip install --upgrade pip
-pip install -r requirements.txt
+pip install -r requirements-dev.txt
 pytest -q
 ```
 
diff --git a/pytest.ini b/pytest.ini
new file mode 100644
index 0000000..07ead03
--- /dev/null
+++ b/pytest.ini
@@ -0,0 +1,5 @@
+[pytest]
+minversion = 7.0
+testpaths = tests
+python_files = test_*.py
+addopts = -q
diff --git a/requirements-dev.txt b/requirements-dev.txt
new file mode 100644
index 0000000..13f6026
--- /dev/null
+++ b/requirements-dev.txt
@@ -0,0 +1,2 @@
+-r requirements.txt
+pytest>=8.0.0
diff --git a/requirements.txt b/requirements.txt
index 0bc8eef..0ffd319 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1 @@
 aiosmtpd>=1.4.6,<1.5
-pytest>=8.0.0