diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2ae56dd..269302b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,8 +1,10 @@
 name: CI
 
 on:
+  # No branch filter: `branches` matches a pull request's base, so restricting
+  # it to main skipped CI entirely on stacked pull requests, which target the
+  # branch below them rather than main.
   pull_request:
-    branches: [main]
 
 permissions:
   contents: read
@@ -29,9 +31,14 @@ jobs:
       - name: Install dependencies
         run: bun install
 
+      # Must run after the build: benchmarks/joyful.bench.ts imports from
+      # dist, so typecheck fails on a clean checkout without it.
       - name: Build
         run: bun run build
 
+      - name: Lint and typecheck
+        run: bun run check
+
       - name: Run tests
         run: bun test