diff --git a/vorlesung/L05_binaere_baeume/bin_tree.py b/vorlesung/L05_binaere_baeume/bin_tree.py
index 6e9caa6..49e12a8 100644
--- a/vorlesung/L05_binaere_baeume/bin_tree.py
+++ b/vorlesung/L05_binaere_baeume/bin_tree.py
@@ -40,10 +40,11 @@ class BinaryTree:
 
     def search(self, value):
         current = self.root
+        value = self.new_node(value)
         while current:
-            if value < current.value:
+            if value < current:
                 current = current.left
-            elif value > current.value:
+            elif value > current:
                 current = current.right
             else:
                 return current
@@ -55,11 +56,12 @@ class BinaryTree:
         # der Knoten, der den zu löschenden Knoten ersetzt und der Elternknoten des gelöschten Knotens
         parent = None
         current = self.root
+        value = self.new_node(value)
         while current:
-            if value < current.value:
+            if value < current:
                 parent = current
                 current = current.left
-            elif value > current.value:
+            elif value > current:
                 parent = current
                 current = current.right
             else:
@@ -98,7 +100,7 @@ class BinaryTree:
         if not parent:
             self.root = child
             return child, None
-        elif parent.left == current:
+        elif parent.left is current:
             parent.left = child
             return child, parent
         else: