diff --git a/src/core/Definitions/Metadata.php b/src/core/Definitions/Metadata.php
index 72e4d95b9a..80405e752e 100644
--- a/src/core/Definitions/Metadata.php
+++ b/src/core/Definitions/Metadata.php
@@ -218,7 +218,7 @@ function getDefaultSerializer() {
                 }
             },
             'multiselect' => function($value){
-                $value = array_filter($value);
+                $value = $value ? array_filter($value) : [];
                 return json_encode($value);
             },
             'location' => function($value) {