diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 30194a43..cd93b347 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -385,7 +385,7 @@ jobs:
           fi
 
           npx node-gyp install
-          yarn install --immutable
+          yarn install
 
           yarn --cwd arduino-ide-extension build
           yarn --cwd electron-app rebuild
diff --git a/.github/workflows/check-yarn.yml b/.github/workflows/check-yarn.yml
new file mode 100644
index 00000000..3b2efe92
--- /dev/null
+++ b/.github/workflows/check-yarn.yml
@@ -0,0 +1,91 @@
+name: Check Yarn
+
+# See: https://docs.github.com/en/actions/reference/events-that-trigger-workflows
+on:
+  create:
+  push:
+    paths:
+      - ".github/workflows/check-yarn.ya?ml"
+      - "**/.yarnrc"
+      - "**/package.json"
+      - "**/package-lock.json"
+      - "**/yarn.lock"
+  pull_request:
+    paths:
+      - ".github/workflows/check-yarn.ya?ml"
+      - "**/.yarnrc"
+      - "**/package.json"
+      - "**/package-lock.json"
+      - "**/yarn.lock"
+  schedule:
+    # Run every Tuesday at 8 AM UTC to catch breakage resulting from changes to the JSON schema.
+    - cron: "0 8 * * TUE"
+  workflow_dispatch:
+  repository_dispatch:
+
+jobs:
+  run-determination:
+    runs-on: ubuntu-latest
+    permissions: {}
+    outputs:
+      result: ${{ steps.determination.outputs.result }}
+    steps:
+      - name: Determine if the rest of the workflow should run
+        id: determination
+        run: |
+          RELEASE_BRANCH_REGEX="refs/heads/[0-9]+.[0-9]+.x"
+          # The `create` event trigger doesn't support `branches` filters, so it's necessary to use Bash instead.
+          if [[
+            "${{ github.event_name }}" != "create" ||
+            "${{ github.ref }}" =~ $RELEASE_BRANCH_REGEX
+          ]]; then
+            # Run the other jobs.
+            RESULT="true"
+          else
+            # There is no need to run the other jobs.
+            RESULT="false"
+          fi
+
+          echo "result=$RESULT" >> $GITHUB_OUTPUT
+
+  check-sync:
+    name: check-sync (${{ matrix.project.path }})
+    needs: run-determination
+    if: needs.run-determination.outputs.result == 'true'
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+
+    strategy:
+      fail-fast: false
+      matrix:
+        project:
+          - path: .
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          cache: yarn
+          node-version: ${{ env.NODE_VERSION }}
+
+      - name: Install npm package dependencies
+        env:
+          # Avoid failure of @vscode/ripgrep installation due to GitHub API rate limiting:
+          # https://github.com/microsoft/vscode-ripgrep#github-api-limit-note
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          yarn \
+            install \
+            --ignore-scripts
+
+      - name: Check yarn.lock
+        run: |
+          git \
+            diff \
+              --color \
+              --exit-code \
+              "${{ matrix.project.path }}/yarn.lock"