diff --git a/.github/workflows/benchmark.yml b/.github/workflows/benchmark.yml
index ddc860f1b..43f918a82 100644
--- a/.github/workflows/benchmark.yml
+++ b/.github/workflows/benchmark.yml
@@ -67,9 +67,7 @@ jobs:
       - name: install & build (base branch)
         working-directory: ${{ env.ROOT }}-main
         run: |
-          # A base branch that predates package-lock.json is still a yarn project:
-          # npm can't install it (babel-loader@7's stale webpack peer range).
-          if [ -f package-lock.json ]; then npm ci; else npx --yes yarn@1 install --frozen-lockfile; fi
+          npm ci
           npm run build
 
       # --root-a is the PR branch built by the build-ts-loader action;