diff --git a/src/Harvester.php b/src/Harvester.php
index 1a96dfb..eccefd6 100644
--- a/src/Harvester.php
+++ b/src/Harvester.php
@@ -20,7 +20,7 @@ public function __construct(Factory $factory)
 
     public function revert()
     {
-        $ids = array_keys($this->factory->hashStorage->retrieveAll());
+        $ids = $this->factory->hashStorage->retrieveAll();
         $load = $this->factory->get("load");
         $counter = 0;
         foreach ($ids as $id) {
diff --git a/src/ResultInterpreter.php b/src/ResultInterpreter.php
index 6738a80..2fc733c 100644
--- a/src/ResultInterpreter.php
+++ b/src/ResultInterpreter.php
@@ -1,6 +1,5 @@
 <?php
 
-
 namespace Harvest;
 
 class ResultInterpreter
diff --git a/test/MemStore.php b/test/MemStore.php
index b08ef2f..af5becf 100644
--- a/test/MemStore.php
+++ b/test/MemStore.php
@@ -7,5 +7,9 @@
 
 class MemStore extends Memory implements StorageInterface
 {
+    public function retrieveAll(): array
+    {
+        return array_keys(parent::retrieveAll());
+    }
 
 }