diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d93e146..c9936f3 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,21 +1,41 @@
 name: CI
 
 on:
-  push:
   pull_request:
+  push:
+    branches:
+      - main
+  workflow_dispatch:
 
 permissions:
   contents: read
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   validate:
+    name: Validate and test
     runs-on: ubuntu-latest
+    timeout-minutes: 5
+
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - name: Check out repository
+        uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
+        with:
+          persist-credentials: false
+
+      - name: Set up Python
+        uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5
         with:
           python-version: "3.12"
-      - name: Validate repository
-        run: python3 scripts/check_repository.py
+
+      - name: Compile Python
+        run: python -m compileall -q scripts tests
+
+      - name: Validate repository files
+        run: python scripts/check_repository.py
+
       - name: Run tests
-        run: python3 -m unittest discover -s tests -v
+        run: python -m unittest discover --start-directory tests --verbose