diff --git a/gestion/lib/Service/InvoicePdfService.php b/gestion/lib/Service/InvoicePdfService.php
index f729062..0e790f5 100644
--- a/gestion/lib/Service/InvoicePdfService.php
+++ b/gestion/lib/Service/InvoicePdfService.php
@@ -124,8 +124,8 @@ class InvoicePdfService {
 		$currentConfig = $configs[0];
         $logo = $this->getLogo();
         $invoiceData = $this->gestionBdd->getInvoicePdfDataByClientAndMonthYear($clientId,$month,$year,$currentConfig);
-        if($invoiceData == null){
-			return "";
+        if(empty($invoiceData)){
+			return null;
 		}
         $pdf = new InvoicePdfHandler();
         $pdf->MutlipleInvoicePdfFactory($invoiceData,$logo);