diff --git a/src/tree.c b/src/tree.c
index c665392..5543ef4 100644
--- a/src/tree.c
+++ b/src/tree.c
@@ -1875,8 +1875,6 @@ bool tree_avl_delete(struct _tree* self, void* obj)
     {
         return false;
     }
-    // debug
-    self->print_obj(obj);
 
     if((node->left != NULL) && (node->right != NULL))
     {
@@ -2110,7 +2108,7 @@ static struct _tree_node* tree_find_min(struct _tree* self, struct _tree_node* r
     }
     return tree_find_min(self, root->left);
 #else
-    while(root == NULL)
+    while(root != NULL)
     {
         if(root->left != NULL)
         {
@@ -2118,7 +2116,7 @@ static struct _tree_node* tree_find_min(struct _tree* self, struct _tree_node* r
         }
         else
         {
-            break;
+            return root;
         }
     }
     return root;
diff --git a/test/test_tree.c b/test/test_tree.c
index c63ea3e..953a875 100644
--- a/test/test_tree.c
+++ b/test/test_tree.c
@@ -340,8 +340,8 @@ void test_tree_num(void)
 
     printf("----- left priority -----\n");
     tree->order(tree, false);
-    printf("----- breadth -----\n");
-    tree->breadth(tree, tree->_root);
+    printf("----- preorder -----\n");
+    tree->preorder(tree, tree->_root);
     printf("\n");
 
     for (i = 0; i < len; i++)
@@ -350,9 +350,11 @@ void test_tree_num(void)
 
         printf("delete = ");
         tree->print_obj(&temp);
+        // delete
+        tree->delete(tree, &temp);
+
         printf("size = %2d : ", tree->size(tree));
 
-        tree->delete(tree, &temp);
 
         // printf("----- breadth -----\n");
         // tree->breadth(tree, tree->_root);