diff --git a/lib/file_tree.rb b/lib/file_tree.rb
index 714db77a..5ee6b2b0 100644
--- a/lib/file_tree.rb
+++ b/lib/file_tree.rb
@@ -23,7 +23,7 @@ class FileTree < Tree::TreeNode
   end
   private :folder_icon
 
-  def initialize(files)
+  def initialize(files = [])
     super(root_label)
     files.each do |file|
       parent = self