diff --git a/eng/common/scripts/Generate-PR-Diff.ps1 b/eng/common/scripts/Generate-PR-Diff.ps1
index 3b508b1cb..5c3d76400 100644
--- a/eng/common/scripts/Generate-PR-Diff.ps1
+++ b/eng/common/scripts/Generate-PR-Diff.ps1
@@ -41,8 +41,13 @@ if (!(Test-Path $ArtifactPath))
 $ArtifactPath = Resolve-Path $ArtifactPath
 $ArtifactName = Join-Path $ArtifactPath "diff.json"
 
+$changedFiles = @()
+$changedServices = @()
+
 $changedFiles = Get-ChangedFiles -DiffPath $TargetPath
-$changedServices = Get-ChangedServices -ChangedFiles $changedFiles
+if ($changedFiles) {
+  $changedServices = Get-ChangedServices -ChangedFiles $changedFiles
+}
 
 $result = [PSCustomObject]@{
   "ChangedFiles"    = $changedFiles