diff --git a/bintree.c b/bintree.c
index a1e0e34..90e963f 100644
--- a/bintree.c
+++ b/bintree.c
@@ -79,11 +79,8 @@ void *nextTreeData(TreeNode *root) {
     TreeNode *currentNode = root;
     while (currentNode !=
            NULL) { // alle linken Knoten werden vom root an auf den Stack gelegt
-      StackNode *oldStack = stack;
-      StackNode *newStack = push(stack, currentNode);
-      if (newStack == oldStack)
-        return NULL; // push fehlgeschlagen
-      stack = newStack;
+
+      stack = push(stack, currentNode);
       currentNode = currentNode->left;
     }
   }
@@ -98,11 +95,7 @@ void *nextTreeData(TreeNode *root) {
   // Rechten Teilbaum pushen
   TreeNode *currentNode = node->right;
   while (currentNode != NULL) {
-    StackNode *oldStack = stack;
-    StackNode *newStack = push(stack, currentNode);
-    if (newStack == oldStack)
-      return NULL; // push fehlgeschlagen
-    stack = newStack;
+    stack = push(stack, currentNode);
     currentNode = currentNode->left;
   }
   return node->data; // Pointer auf Daten