diff --git a/cv4/list_ops.c b/cv4/list_ops.c
index 148e985..f066239 100644
--- a/cv4/list_ops.c
+++ b/cv4/list_ops.c
@@ -20,12 +20,13 @@ list_t *new_list(size_t length, list_element_t elements[]) {
 
 list_t *append_list(list_t *list1, list_t *list2) {
     size_t length1 = list1->length + list2->length;
-    list_t *list3 = new_list(length1, list1->elements);
+    list_t *list3 = new_list(length1, NULL);
     if (!list3) {
         return NULL;
     }
+    memcpy(list3->elements, list1->elements, list1->length * sizeof(list_element_t));
     memcpy(list3->elements + list1->length, list2->elements, list2->length * sizeof(list_element_t));
-    list3->length = list1->length + list2->length;
+    list3->length = length1;
     return list3;
 }