diff --git a/08-vyrazy/objektove.py b/08-vyrazy/objektove.py
index 90b0d458a9cc3f7719d76956bd76baa96b88048b..645354f8b99ebe6c237c63ba6ad34f9589ea13d9 100755
--- a/08-vyrazy/objektove.py
+++ b/08-vyrazy/objektove.py
@@ -11,7 +11,7 @@
 class Node:
 
     def eval(self):
-        raise NotImplemented()
+        raise NotImplementedError()
 
 
 class NumNode(Node):
diff --git a/08-vyrazy/objektove2.py b/08-vyrazy/objektove2.py
index 1a4de578bb76ce0a24fc7f05442466907f37b12d..6295851f5cfb56370a21b1210cb6514240706a09 100755
--- a/08-vyrazy/objektove2.py
+++ b/08-vyrazy/objektove2.py
@@ -13,7 +13,7 @@
 class Node:
 
     def eval(self):
-        raise NotImplemented()
+        raise NotImplementedError()
 
 
 class NumNode(Node):
diff --git a/08-vyrazy/strom-vyrazu.py b/08-vyrazy/strom-vyrazu.py
index e2cab566445d8e789c7a2b57d606781706daf49d..44b962d13a193fdf742c2dd74ddcdb7d7e74dc48 100755
--- a/08-vyrazy/strom-vyrazu.py
+++ b/08-vyrazy/strom-vyrazu.py
@@ -35,10 +35,10 @@ class Node:
                 return l * r
             if op == '/':
                 return l // r
-            raise NotImplemented()
+            raise NotImplementedError()
 
 
 x = Node('+', Node('*', Node(3), Node(4)), Node('-', Node(5), Node(6)))
-# print(x)
+print(x)
 x.print_tree()
 print(x.eval())