diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 23d3e71424b..2770bded30a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -71,6 +71,11 @@ jobs:
         uses: actions/checkout@v3
         with:
           fetch-depth: 2
+      - name: "checkout the `master` branch for tidy"
+        uses: actions/checkout@v3
+        with:
+          ref: master
+          fetch-depth: 1
       - name: configure the PR in which the error message will be posted
         run: "echo \"[CI_PR_NUMBER=$num]\""
         env:
@@ -485,6 +490,11 @@ jobs:
         uses: actions/checkout@v3
         with:
           fetch-depth: 2
+      - name: "checkout the `master` branch for tidy"
+        uses: actions/checkout@v3
+        with:
+          ref: master
+          fetch-depth: 1
       - name: configure the PR in which the error message will be posted
         run: "echo \"[CI_PR_NUMBER=$num]\""
         env:
@@ -600,6 +610,11 @@ jobs:
         uses: actions/checkout@v3
         with:
           fetch-depth: 2
+      - name: "checkout the `master` branch for tidy"
+        uses: actions/checkout@v3
+        with:
+          ref: master
+          fetch-depth: 1
       - name: configure the PR in which the error message will be posted
         run: "echo \"[CI_PR_NUMBER=$num]\""
         env:
diff --git a/src/ci/github-actions/ci.yml b/src/ci/github-actions/ci.yml
index d33396dcc80..d3b07419486 100644
--- a/src/ci/github-actions/ci.yml
+++ b/src/ci/github-actions/ci.yml
@@ -103,6 +103,12 @@ x--expand-yaml-anchors--remove:
         with:
           fetch-depth: 2
 
+      - name: checkout the `master` branch for tidy
+        uses: actions/checkout@v3
+        with:
+          ref: master
+          fetch-depth: 1
+
       # Rust Log Analyzer can't currently detect the PR number of a GitHub
       # Actions build on its own, so a hint in the log message is needed to
       # point it in the right direction.