diff --git a/eng/common/scripts/Prepare-Release.ps1 b/eng/common/scripts/Prepare-Release.ps1
index 269fd113..e82c5982 100644
--- a/eng/common/scripts/Prepare-Release.ps1
+++ b/eng/common/scripts/Prepare-Release.ps1
@@ -116,7 +116,7 @@ $month = $ParsedReleaseDate.ToString("MMMM")
 Write-Host "Assuming release is in $month with release date $releaseDateString" -ForegroundColor Green
 if (Test-Path "Function:GetExistingPackageVersions")
 {
-    $releasedVersions = GetExistingPackageVersions -PackageName $packageProperties.Name -GroupId $packageProperties.Group
+    $releasedVersions = @(GetExistingPackageVersions -PackageName $packageProperties.Name -GroupId $packageProperties.Group)
     if ($null -ne $releasedVersions -and $releasedVersions.Count -gt 0)
     {
       $latestReleasedVersion = $releasedVersions[$releasedVersions.Count - 1]