diff --git a/lib/droonga/catalog/version2.rb b/lib/droonga/catalog/version2.rb
index 11bb4a33..99fc3674 100644
--- a/lib/droonga/catalog/version2.rb
+++ b/lib/droonga/catalog/version2.rb
@@ -47,7 +47,7 @@ def slices(node)
                 name = volume_address.name
                 migrate_database_location(device, name)
 
-                path = File.join([device, Path.databases.basename.to_s, name, "db"])
+                path = File.join(device, Path.databases.basename.to_s, name, "db")
                 path = Pathname(path).expand_path(base_path)
                 options = {
                   :dataset => dataset_name,