diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2bea69ae..ba20d8cb 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -111,3 +111,13 @@ jobs:
       # Python, so no uv sync / deps needed.
       - name: triage.md is up to date with triage.jsonl
         run: make triage-check
+
+  ui-lockfile:
+    name: ui bun.lock in sync
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+      - uses: oven-sh/setup-bun@v2
+      - name: ui/package.json and ui/bun.lock agree
+        working-directory: ui
+        run: bun install --frozen-lockfile
\ No newline at end of file