diff --git a/polkadot/.github/workflows/check-labels.yml b/polkadot/.github/workflows/check-labels.yml
index 66e37b65fe..e70bfddfd3 100644
--- a/polkadot/.github/workflows/check-labels.yml
+++ b/polkadot/.github/workflows/check-labels.yml
@@ -19,3 +19,4 @@ jobs:
           GITHUB_PR: ${{ github.event.pull_request.number }}
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           HEAD_SHA: ${{ github.event.pull_request.head.sha }}
+          BASE_SHA: ${{ github.event.pull_request.base.sha }}
diff --git a/polkadot/scripts/github/check_labels.sh b/polkadot/scripts/github/check_labels.sh
index e18272ec8e..12f07b3495 100755
--- a/polkadot/scripts/github/check_labels.sh
+++ b/polkadot/scripts/github/check_labels.sh
@@ -54,7 +54,7 @@ else
   exit 1
 fi
 
-if has_runtime_changes origin/master "${HEAD_SHA}"; then
+if has_runtime_changes "${BASE_SHA}" "${HEAD_SHA}"; then
   echo "[+] Runtime changes detected. Checking audit (D) labels"
   if ensure_labels "${audit_labels[@]}";  then
     echo "[+] Release audit label detected. All is well."