diff --git a/I2_Dobble/bintreeTest.c b/I2_Dobble/bintreeTest.c
index 588060b..699a594 100644
--- a/I2_Dobble/bintreeTest.c
+++ b/I2_Dobble/bintreeTest.c
@@ -29,7 +29,7 @@ void test_addToTree_multiple_elements_and_size(void)
 {
     TreeNode *root = NULL;
     int values[] = {5, 3, 7, 1, 4};
-    int dup = -1;
+    int dup = 0;
 
     for (int i = 0; i < 5; i++)
         root = addToTree(root, &values[i], sizeof(int), compare, &dup);