diff --git a/lib/train/transports/mock.rb b/lib/train/transports/mock.rb
index 86e9640f..bd5195cc 100644
--- a/lib/train/transports/mock.rb
+++ b/lib/train/transports/mock.rb
@@ -115,11 +115,11 @@ class File < FileCommon
       attr_accessor m.tr('?', '').to_sym
     end
 
-    def initialize(_runtime, path)
+    def initialize(runtime, path)
       @path = path
       @type = :unknown
       @exist = false
-      @runtime = _runtime
+      @runtime = runtime
     end
 
     def mounted