diff --git a/.github/workflows/build_and_publish.yaml b/.github/workflows/build_and_publish.yaml
index 762feb88..e3bbde6b 100644
--- a/.github/workflows/build_and_publish.yaml
+++ b/.github/workflows/build_and_publish.yaml
@@ -18,7 +18,7 @@ permissions:
 
 jobs:
   tag-new-version:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     outputs:
       tag: ${{ steps.tag.outputs.new_tag }}
       version: ${{ steps.tag.outputs.new_version }}
@@ -51,13 +51,15 @@ jobs:
         just docker/build prod # explicitly build prod as well
     - name: Test image
       run: just docker/test
+    - name: Functional teste
+      run: just docker/functional-test
     - name: Log into GitHub Container Registry
       run: docker login https://ghcr.io -u ${{ github.actor }} --password ${{ secrets.GITHUB_TOKEN }}
     - name: Push image to GitHub Container Registry
       run: |
-        IMAGE_ID=ghcr.io/${{ github.repository_owner }}/$IMAGE_NAME
-        docker tag $IMAGE_NAME $IMAGE_ID:latest
-        docker push $IMAGE_ID:latest
+        IMAGE_ID="ghcr.io/${{ github.repository_owner }}/$IMAGE_NAME"
+        docker tag "$IMAGE_NAME" "$IMAGE_ID:latest"
+        docker push "$IMAGE_ID:latest"
 
   create-release-from-tag:
     name: Create release from tag
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index deb0309c..7eb5959c 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -10,7 +10,7 @@ env:
 
 jobs:
   check:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
 
     steps:
       - uses: actions/checkout@v4
@@ -26,13 +26,15 @@ jobs:
   test-job:
     strategy:
       matrix:
-        os: [ubuntu-20.04, ubuntu-22.04, windows-2019, macos-12]
+        os: [ubuntu-22.04, windows-2019, macos-12]
         # Python 3.8 is what we currently support for running cohortextractor
         # locally, and 3.9 is what we required for databuilder so we need to make
         # sure we can run with those
         python: ["3.8", "3.9", "3.10"]
     runs-on: ${{ matrix.os }}
     name: Run test suite
+    env: 
+        PYTHON_VERSION: ${{ matrix.python }}
     steps:
       - name: Checkout
         uses: actions/checkout@v4
@@ -65,7 +67,7 @@ jobs:
       - uses: extractions/setup-just@69d82fb0233557aec017ef13706851d0694e0f1d
 
       - name: Run actual tests on ${{ matrix.os }}
-        if: ${{ matrix.os == 'ubuntu-20.04' }}
+        if: ${{ matrix.os == 'ubuntu-22.04' }}
         run: just test -vvv
 
       - name: Run actual tests on ${{ matrix.os }}
@@ -73,7 +75,7 @@ jobs:
         run: just test-no-docker -vvv
 
   test-package-build:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     name: Test we can build PyPI package
     steps:
       - name: Checkout
@@ -100,7 +102,7 @@ jobs:
         run: just package-test sdist
 
   test-docker:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     name: Test docker image
     steps:
       - name: Checkout
@@ -117,8 +119,11 @@ jobs:
       - name: Run tests in docker-image
         run: just docker/test
 
+      - name: Run functional test
+        run: just docker/functional-test
+
   test-github-workflow-output:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     name: Inspect test runner output in the context of a Github Workflow
     steps:
       - name: Checkout