diff --git a/src/Bundle/ChillMainBundle/Controller/ExportController.php b/src/Bundle/ChillMainBundle/Controller/ExportController.php
index 693c0e55e..d623a2613 100644
--- a/src/Bundle/ChillMainBundle/Controller/ExportController.php
+++ b/src/Bundle/ChillMainBundle/Controller/ExportController.php
@@ -345,7 +345,7 @@ class ExportController extends AbstractController
      * @param array  $dataExport    Raw data from export step
      * @param array  $dataFormatter Raw data from formatter step
      */
-    private function buildExportDataForNormalization(string $alias, ?array $dataCenters, array $dataExport, array $dataFormatter, ?SavedExport $savedExport): array
+    private function buildExportDataForNormalization(?string $alias, ?array $dataCenters, array $dataExport, ?array $dataFormatter, ?SavedExport $savedExport): array
     {
         if ($this->filterStatsByCenters) {
             $formCenters = $this->createCreateFormExport($alias, 'generate_centers', [], null);