diff --git a/src/Aggregate/StreamNameTranslator.php b/src/Aggregate/StreamNameTranslator.php
index e3030b341..00c74bf98 100644
--- a/src/Aggregate/StreamNameTranslator.php
+++ b/src/Aggregate/StreamNameTranslator.php
@@ -14,6 +14,7 @@ private function __construct()
     {
     }
 
+    /** @pure */
     public static function streamName(string $aggregate, string $aggregateId): string
     {
         return $aggregate . '-' . $aggregateId;