diff --git a/.github/workflows/pr-code-format.yml b/.github/workflows/pr-code-format.yml
index b08e5c21ca62e..2c06c8bdddea6 100644
--- a/.github/workflows/pr-code-format.yml
+++ b/.github/workflows/pr-code-format.yml
@@ -21,14 +21,7 @@ jobs:
       - name: Fetch LLVM sources
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
-          ref: ${{ github.event.pull_request.head.sha }}
-
-      - name: Checkout through merge base
-        uses: rmacklin/fetch-through-merge-base@bfe4d03a86f9afa52bc1a70e9814fc92a07f7b75 # v0.3.0
-        with:
-          base_ref: ${{ github.event.pull_request.base.ref }}
-          head_ref: ${{ github.event.pull_request.head.sha }}
-          deepen_length: 500
+          fetch-depth: 2
 
       - name: Get changed files
         id: changed-files
@@ -36,6 +29,8 @@ jobs:
         with:
           separator: ","
           skip_initial_fetch: true
+          base_sha: 'HEAD~1'
+          sha: 'HEAD'
 
       # We need to pull the script from the main branch, so that we ensure
       # we get the latest version of this script.
@@ -89,8 +84,8 @@ jobs:
             --write-comment-to-file \
             --token ${{ secrets.GITHUB_TOKEN }} \
             --issue-number $GITHUB_PR_NUMBER \
-            --start-rev $(git merge-base $START_REV $END_REV) \
-            --end-rev $END_REV \
+            --start-rev HEAD~1 \
+            --end-rev HEAD \
             --changed-files "$CHANGED_FILES"
 
       - uses: actions/upload-artifact@26f96dfa697d77e81fd5907df203aa23a56210a8 #v4.3.0