diff --git a/system/src/Grav/Framework/Flex/Storage/FolderStorage.php b/system/src/Grav/Framework/Flex/Storage/FolderStorage.php
index bb7ad2e70..db88f348e 100644
--- a/system/src/Grav/Framework/Flex/Storage/FolderStorage.php
+++ b/system/src/Grav/Framework/Flex/Storage/FolderStorage.php
@@ -398,7 +398,11 @@ class FolderStorage extends AbstractFilesystemStorage
             $list[] = $this->findKeysFromFilesystem($filename);
         }
 
-        return array_merge(...$list);
+        if (!$list) {
+            return [];
+        }
+
+        return \count($list) > 1 ? array_merge(...$list) : $list[0];
     }
 
     /**