diff --git a/src/MsrcSecurityUpdates/Public/Get-MsrcVulnerabilityReportHtml.ps1 b/src/MsrcSecurityUpdates/Public/Get-MsrcVulnerabilityReportHtml.ps1
index 3bf9f1e..8afb526 100644
--- a/src/MsrcSecurityUpdates/Public/Get-MsrcVulnerabilityReportHtml.ps1
+++ b/src/MsrcSecurityUpdates/Public/Get-MsrcVulnerabilityReportHtml.ps1
@@ -46,7 +46,7 @@ Function Get-MsrcVulnerabilityReportHtml {
 Param(
 
     [Parameter(Mandatory,ValueFromPipelineByPropertyName)]
-    $Vulnerability,
+    [array]$Vulnerability,
 
     [Parameter(Mandatory,ValueFromPipelineByPropertyName)]
     $ProductTree,