diff --git a/.github/workflows/automated-deploy-stack.yml b/.github/workflows/automated-deploy-stack.yml
index 6f34935d..d859748a 100644
--- a/.github/workflows/automated-deploy-stack.yml
+++ b/.github/workflows/automated-deploy-stack.yml
@@ -68,8 +68,12 @@ jobs:
           if [ "$GITHUB_EVENT_NAME" == "pull_request" ]; then
             changed=$(git diff --name-only origin/main... | tr '\n' ' ')
           fi
-          echo "DEBUG: Changed files: '$changed'"
-          echo "changed=$changed" >> $GITHUB_OUTPUT
+          if [ -z "$changed" ]; then
+            echo "No changed files detected."
+          else
+            echo "DEBUG: Changed files: '$changed'"
+            echo "changed=$changed" >> $GITHUB_OUTPUT
+          fi
 
   deductions-ci:
     if: contains(needs.get-changed-files.outputs.changed, 'stacks/mesh-forwarder') || contains(needs.get-changed-files.outputs.changed, '.github/workflows/automated-deploy-stack.yml')
diff --git a/.github/workflows/deploy-stack.yml b/.github/workflows/deploy-stack.yml
index c61cfc46..7ac0dbaf 100644
--- a/.github/workflows/deploy-stack.yml
+++ b/.github/workflows/deploy-stack.yml
@@ -69,6 +69,11 @@ on:
         default: false
         description: "Do we need to build any lambdas before deploying?"
         type: boolean
+      workflow_version:
+        default: v3
+        description: "The workflow version to use when calling this workflow from another repo - e.g. v3"
+        type: string
+        required: false
 
 permissions:
   pull-requests: write
@@ -151,7 +156,7 @@ jobs:
         with:
           repository: NHSDigital/orphaned-record-continuity-infrastructure
           fetch-depth: 0
-          ref: ${{ github.ref }}
+          ref: ${{ !contains(github.repository, 'infrastructure') && inputs.workflow_version || github.ref }}
 
       - name: Configure AWS Credentials (ReadWrite)
         uses: aws-actions/configure-aws-credentials@8df5847569e6427dd6c4fb1cf565c83acfa8afa7 # v6.0.0