diff --git a/htdocs/compta/facture/class/api_invoices.class.php b/htdocs/compta/facture/class/api_invoices.class.php
index 4efc997cc42..a5f1fe92999 100644
--- a/htdocs/compta/facture/class/api_invoices.class.php
+++ b/htdocs/compta/facture/class/api_invoices.class.php
@@ -191,7 +191,7 @@ class Invoices extends DolibarrApi
         foreach($request_data as $field => $value) {
             $this->invoice->$field = $value;
         }
-        if(! array_keys($request_data,'date')) {
+        if(! array_key_exists('date', $request_data)) {
             $this->invoice->date = dol_now();
         }
         /* We keep lines as an array