diff --git a/src/Fields/MediaField.php b/src/Fields/MediaField.php
index 65cf1ab..6cc1c3f 100644
--- a/src/Fields/MediaField.php
+++ b/src/Fields/MediaField.php
@@ -86,7 +86,7 @@ protected function fillAttributeFromRequest(NovaRequest $request, $requestAttrib
      */
     protected function resolveAttribute($resource, $attribute)
     {
-        $customProperties = $this->mediaLibraryMethods['withCustomProperties'] ?? [];
+        $customProperties = $this->mediaLibraryMethods['withCustomProperties'] ?? '';
         $media = $resource->getMedia($this->mediaCollection);
 
         if (!empty($customProperties)) {