diff --git a/htdocs/fourn/class/api_supplier_invoices.class.php b/htdocs/fourn/class/api_supplier_invoices.class.php
index 416f7e11e94..f4918650dc7 100644
--- a/htdocs/fourn/class/api_supplier_invoices.class.php
+++ b/htdocs/fourn/class/api_supplier_invoices.class.php
@@ -200,7 +200,7 @@ class SupplierInvoices 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