diff --git a/.github/requirements-earliest.txt b/.github/requirements-earliest.txt
new file mode 100644
index 0000000..cc72e71
--- /dev/null
+++ b/.github/requirements-earliest.txt
@@ -0,0 +1 @@
+mercurial==5.2
diff --git a/.github/requirements-latest.txt b/.github/requirements-latest.txt
new file mode 100644
index 0000000..3620838
--- /dev/null
+++ b/.github/requirements-latest.txt
@@ -0,0 +1,2 @@
+mercurial
+
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 57efee7..e511200 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -8,8 +8,70 @@ on:
     branches: [master]
 
 jobs:
-  test:
-    name: Run test suite
+  test-earliest:
+    name: Run test suite on the earliest supported Python version
+    runs-on: ubuntu-20.04
+
+    steps:
+      - uses: actions/checkout@v4
+        name: Checkout repository
+        with:
+          fetch-depth: 1
+          submodules: 'recursive'
+      - uses: actions/setup-python@v5
+        id: earliest
+        with:
+          python-version: '3.7.x'
+          check-latest: true
+          cache: 'pip'
+          cache-dependency-path: '**/requirements-earliest.txt'
+
+      - name: Install dependencies
+        run: |
+            python -m pip install --upgrade pip
+            pip install -r .github/requirements-earliest.txt
+
+      - name: Report selected versions
+        run: |
+          echo Selected '${{ steps.earliest.outputs.python-version }}'
+          ./hg-fast-export.sh --debug
+
+      - name: Run tests on earliest supported Python version
+        run: make -C t
+
+  test-latest:
+    name: Run test suite on the latest supported python version
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+        name: Checkout repository
+        with:
+          fetch-depth: 1
+          submodules: 'recursive'
+      - uses: actions/setup-python@v5
+        id: latest
+        with:
+          python-version: '3.x'
+          check-latest: true
+          cache: 'pip'
+          cache-dependency-path: '**/requirements-latest.txt'
+
+      - name: Install dependencies
+        run: |
+            python -m pip install --upgrade pip
+            pip install -r .github/requirements-latest.txt
+
+      - name: Report selected version
+        run: |
+          echo Selected '${{ steps.latest.outputs.python-version }}'
+          ./hg-fast-export.sh --debug
+
+      - name: Run tests on 3.x
+        run: make -C t
+
+  code-quality:
+    name: Run code quality checks
     runs-on: ubuntu-latest
 
     steps:
@@ -19,9 +81,6 @@ jobs:
         fetch-depth: 1
         submodules: 'recursive'
 
-    - name: Run tests
-      run: make -C t
-
     - name: Initialize CodeQL
       uses: github/codeql-action/init@v2
       with: