diff --git a/binary_tree_tutorial.txt b/binary_tree_tutorial.txt
index 5cb7162..33c6d13 100644
--- a/binary_tree_tutorial.txt
+++ b/binary_tree_tutorial.txt
@@ -417,7 +417,7 @@ class Node:
 
 For example, we want to access the tree nodes using a for loop:
 [code lang="python"]
-for data in root.tree_data:
+for data in root.tree_data():
   print data
 [/code]