diff --git a/01_binary_search_trees/bst.py b/01_binary_search_trees/bst.py
index 561ca41..163475b 100644
--- a/01_binary_search_trees/bst.py
+++ b/01_binary_search_trees/bst.py
@@ -134,4 +134,13 @@ class BinarySearchNode():
         """
         prints a single tree node.
         """
-        return (str(self.left_child.value) + " " +  str(self.value) + " " + str(self.right_child.value) )
\ No newline at end of file
+        ret = ""
+        if self.has_left_child():
+            ret += str(self.left_child.value) + " "
+
+        ret += str(self.value)
+
+        if self.has_right_child():
+            ret += " " + str(self.right_child.value)
+
+        return ret
\ No newline at end of file
diff --git a/01_binary_search_trees/bst_test.py b/01_binary_search_trees/bst_test.py
index badf96b..187a814 100644
--- a/01_binary_search_trees/bst_test.py
+++ b/01_binary_search_trees/bst_test.py
@@ -208,5 +208,9 @@ class test_binary_search_tree(unittest.TestCase):
 
         self.assertEqual(bst.__str__(), "4 6 10")
 
+        self.assertEqual(bst.root_node.right_child.__str__(), "10 16")
+        self.assertEqual(bst.root_node.right_child.right_child.__str__(), "16")
+
+
 if __name__ == '__main__':
     unittest.main()