diff --git a/.github/workflows/test-recent-mainnet-block.yml b/.github/workflows/test-recent-mainnet-block.yml
index eadba2abd..a3d7e6a78 100644
--- a/.github/workflows/test-recent-mainnet-block.yml
+++ b/.github/workflows/test-recent-mainnet-block.yml
@@ -5,10 +5,6 @@ on:
     - cron: "0 */8 * * *"
   workflow_dispatch:
 
-defaults:
-  run:
-    working-directory: packages/hardhat-core
-
 jobs:
   test-recent-mainnet-block:
     name: Test recent mainnet block
@@ -26,8 +22,6 @@ jobs:
 
       - name: Run test
         uses: actions-rs/cargo@v1
-        env:
-          RUSTFLAGS: ${{ matrix.RUSTFLAGS }}
         with:
           command: replay-block
           args: -u ${{ secrets.ALCHEMY_URL }} -c 1
diff --git a/.github/workflows/test-recent-optimism-block.yml b/.github/workflows/test-recent-optimism-block.yml
new file mode 100644
index 000000000..2a6ca25d0
--- /dev/null
+++ b/.github/workflows/test-recent-optimism-block.yml
@@ -0,0 +1,48 @@
+name: Run a recent full Optimism block in the Hardhat Network
+
+on:
+  schedule:
+    - cron: "0 */8 * * *"
+  workflow_dispatch:
+
+jobs:
+  test-recent-optimism-block:
+    name: Test recent Optimism block
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: feat/multichain
+
+      - name: Install Rust (stable)
+        uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          override: true
+
+      - uses: Swatinem/rust-cache@v2
+
+      - name: Cache EDR RPC cache
+        uses: actions/cache@v4
+        with:
+          path: |
+            **/edr-cache
+          key: test-recent-optimism-block-rpc-cache-v1
+
+      - name: Run test
+        uses: actions-rs/cargo@v1
+        with:
+          command: replay-block
+          args: -u ${{ secrets.ALCHEMY_URL }} -c optimism
+
+      - name: Notify failures
+        if: failure()
+        uses: slackapi/slack-github-action@v1.18.0
+        with:
+          payload: |
+            {
+              "workflow_name": "${{ github.workflow }}",
+              "run_url": "${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}"
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.GH_ACTION_NOTIFICATIONS_SLACK_WEBHOOK_URL }}