diff --git a/src/IndexManager.php b/src/IndexManager.php
index 653df37..5ec0c3c 100644
--- a/src/IndexManager.php
+++ b/src/IndexManager.php
@@ -128,7 +128,7 @@ private function getValue($object, string $property, string $type = Index::ATTR_
 
                 return (string) $value;
             case Index::ATTR_TYPE_MVA:
-                throw new ManticoreException('Not implemented yet');
+                return (array) $value;
             case Index::ATTR_TYPE_STRING:
             default:
                 return (string) $value;
diff --git a/src/IndexManagerRegistry.php b/src/IndexManagerRegistry.php
index e6d71e8..4884ccd 100644
--- a/src/IndexManagerRegistry.php
+++ b/src/IndexManagerRegistry.php
@@ -6,8 +6,8 @@
 
 class IndexManagerRegistry
 {
-    private $indexMap;
-    private $classMap;
+    private $indexMap = [];
+    private $classMap = [];
 
     public function addIndexManager(IndexManager $manager)
     {