diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0a334a2..b3729f6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -2,7 +2,7 @@ name: Continuous integration
 on: pull_request
 jobs:
   ci:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
     - name: Checkout
       uses: actions/checkout@v2
@@ -20,7 +20,7 @@ jobs:
     - name: Build examples
       run: make examples
     - name: Typecheck
-      run: npm run-script typecheck
+      run: make typecheck
     - name: Check formatting
       run: make checkformat
     - name: Run tests
diff --git a/package.json b/package.json
index 6d51f38..79d7550 100644
--- a/package.json
+++ b/package.json
@@ -9,8 +9,7 @@
     "./node": "./src/node-worker.js"
   },
   "scripts": {
-    "test": "make test",
-    "typecheck": "tsc"
+    "test": "make test"
   },
   "repository": {
     "type": "git",