diff --git a/.github/workflows/zjit-macos.yml b/.github/workflows/zjit-macos.yml
index 53732103ec..456854510e 100644
--- a/.github/workflows/zjit-macos.yml
+++ b/.github/workflows/zjit-macos.yml
@@ -120,6 +120,12 @@ jobs:
           TESTS: ${{ matrix.tests }}
         continue-on-error: ${{ matrix.continue-on-test_task || false }}
 
+      - uses: ./.github/actions/slack
+        with:
+          label: ${{ matrix.test_task }} ${{ matrix.configure }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
   result:
     if: ${{ always() }}
     name: ${{ github.workflow }} result
diff --git a/.github/workflows/zjit-ubuntu.yml b/.github/workflows/zjit-ubuntu.yml
index 76b5b2c489..8dd4d44fc5 100644
--- a/.github/workflows/zjit-ubuntu.yml
+++ b/.github/workflows/zjit-ubuntu.yml
@@ -162,6 +162,12 @@ jobs:
           TESTS: ${{ matrix.tests }}
         continue-on-error: ${{ matrix.continue-on-test_task || false }}
 
+      - uses: ./.github/actions/slack
+        with:
+          label: ${{ matrix.test_task }} ${{ matrix.configure }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
   result:
     if: ${{ always() }}
     name: ${{ github.workflow }} result