diff --git a/test/rustint/core_test.clj b/test/rustint/core_test.clj
index 5d6d07a..308db39 100644
--- a/test/rustint/core_test.clj
+++ b/test/rustint/core_test.clj
@@ -807,3 +807,12 @@
     ))
   )
 )
+
+(deftest test-cargar-en-ult-reg-01
+  (testing "Test 01 cargar-en-ult-reg"
+    (is (=
+      (cargar-en-ult-reg [[['String "2"] ['i64 6] ['i64 2] ['i64 3] ['i64 0]] [['i64 nil] ['i64 nil]]] 1 'i64 0)
+      [[['String "2"] ['i64 6] ['i64 2] ['i64 3] ['i64 0]] [['i64 nil] ['i64 0]]]
+    ))
+  )
+)