diff --git a/src/Service/ElasticSearch.php b/src/Service/ElasticSearch.php
index 77794f0..afb1db2 100644
--- a/src/Service/ElasticSearch.php
+++ b/src/Service/ElasticSearch.php
@@ -5,6 +5,7 @@
 namespace Webgriffe\Esb\Service;
 
 use Amp;
+use Amp\Promise;
 use Generator;
 use Symfony\Component\Serializer\Exception\ExceptionInterface;
 use Symfony\Component\Serializer\Normalizer\DenormalizerInterface;
@@ -112,26 +113,33 @@ public function indexExists(string $indexName): Amp\Promise
         });
     }
 
-    /**
-     * @param array<array-key, mixed>|null $indexName
-     */
     public function setElasticSearchIndex(string $indexName): Amp\Promise
     {
         return $this->client->createIndex($indexName);
     }
 
-
+    /**
+     * @param string $indexName
+     * @param array<string, mixed> $updateSettingsBody
+     */
     public function setElasticSearchIndexSettings(string $indexName, array $updateSettingsBody = null): Amp\Promise
     {
         return $this->client->updateIndexSettings($indexName, $updateSettingsBody);
     }
 
-
+    /**
+     * @param string $indexName
+     * @param array<string, mixed> $updateMappingBody
+     */
     public function setElasticSearchIndexMapping(string $indexName, array $updateMappingBody = null): Amp\Promise
     {
         return $this->client->updateMappings($indexName, $updateMappingBody);
     }
 
+    /**
+     * @param string $indexName
+     * @param array<string, mixed> $aliasBody
+     */
     public function setElasticSearchIndexAlias(string $indexName, string $aliasName, array $aliasBody = null): Amp\Promise
     {
         return $this->client->createOrUpdateAlias($indexName, $aliasName, $aliasBody);
diff --git a/src/Service/QueueManager.php b/src/Service/QueueManager.php
index 1ce13bb..4e12dfd 100644
--- a/src/Service/QueueManager.php
+++ b/src/Service/QueueManager.php
@@ -111,7 +111,7 @@ public function boot(): Promise
                     );
                 }
 
-                if ($this->flowConfig->getElasticSearchIndexUpdateAliasesBody()) {
+                if ($this->flowConfig->getElasticSearchIndexUpdateAliasesBody() !== null) {
                     $elasticSearchIndexUpdateAliases = $this->flowConfig->getElasticSearchIndexUpdateAliasesBody();
                     foreach ($elasticSearchIndexUpdateAliases as $aliasName => $aliasBody) {
                         yield $this->elasticSearch->setElasticSearchIndexAlias(