diff --git a/.github/workflows/check-source-domain.yml b/.github/workflows/check-source-domain.yml
index 5de48c7c..0a3f5525 100644
--- a/.github/workflows/check-source-domain.yml
+++ b/.github/workflows/check-source-domain.yml
@@ -9,6 +9,9 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
+      - name: Tune GitHub-hosted runner network
+        # https://github.com/actions/runner-images/issues/1187
+        uses: smorimoto/tune-github-hosted-runner-network@v1
       - name: Checkout
         uses: actions/checkout@v4
         with:
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 22b3ad1a..b1154f6e 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -16,6 +16,9 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
+      - name: Tune GitHub-hosted runner network
+        # https://github.com/actions/runner-images/issues/1187
+        uses: smorimoto/tune-github-hosted-runner-network@v1
       - uses: actions/checkout@v4
         with:
           persist-credentials: false