diff --git a/src/NotificationCenter.php b/src/NotificationCenter.php
index e7ba90d..5345ad3 100644
--- a/src/NotificationCenter.php
+++ b/src/NotificationCenter.php
@@ -363,9 +363,11 @@ public function createBasicStampsForNotification(int $id, TokenCollection|array
         $stamps = new StampCollection([new NotificationConfigStamp($notificationConfig)]);
 
         if (null === $locale && ($request = $this->requestStack->getCurrentRequest()) instanceof Request) {
-            $stamps = $stamps
-                ->with(new LocaleStamp(LocaleUtil::formatAsLocale($request->getLocale())))
-            ;
+            $locale = $request->getLocale();
+        }
+
+        if ($locale) {
+            $stamps = $stamps->with(new LocaleStamp(LocaleUtil::formatAsLocale($locale)));
         }
 
         if (!$tokens instanceof TokenCollection) {