diff --git a/du6/list_ops.c b/du6/list_ops.c
index 6353b30..8bfcc8d 100644
--- a/du6/list_ops.c
+++ b/du6/list_ops.c
@@ -10,4 +10,19 @@ list_t *new_list(size_t length, list_element_t elements[]) {
         memcpy(list->elements, elements, sizeof(list_element_t) * length);
     }
     return list;
+}
+list_t *append_list(list_t *list1, list_t *list2) {
+    size_t len1 = list1 ? list1->length : 0;
+    size_t len2 = list2 ? list2->length : 0;
+
+    list_t *result = malloc(sizeof(list_t) + sizeof(list_element_t) * (len1 + len2));
+    if (!result) return NULL;
+
+    result->length = len1 + len2;
+    if (len1 > 0)
+        memcpy(result->elements, list1->elements, sizeof(list_element_t) * len1);
+    if (len2 > 0)
+        memcpy(result->elements + len1, list2->elements, sizeof(list_element_t) * len2);
+
+    return result;
 }
\ No newline at end of file