diff --git a/port/linux/test/pikaMain-test.cpp b/port/linux/test/pikaMain-test.cpp
index 097b94b9e..1b4588823 100644
--- a/port/linux/test/pikaMain-test.cpp
+++ b/port/linux/test/pikaMain-test.cpp
@@ -727,7 +727,6 @@ TEST(pikaMain, list__set__) {
     __platform_printf((char*)"BEGIN\n");
     obj_run(pikaMain, (char*)
     "list = PikaStdData.List()\n"
-    "list.append(1)\n"
     "__set__(list, 0, 2)\n"
     "res = __get__(list, 0)\n"
     "\n"
@@ -770,7 +769,6 @@ TEST(pikaMain, dict__set__get) {
     __platform_printf((char*)"BEGIN\n");
     obj_run(pikaMain, (char*)
     "list = PikaStdData.Dict()\n"
-    "list.set('a', 1)\n"
     "__set__(list, 'a', 2)\n"
     "res = __get__(list, 'a')\n"
     "\n"
diff --git a/src/PikaVM.c b/src/PikaVM.c
index ec1d3774d..dd00e872f 100644
--- a/src/PikaVM.c
+++ b/src/PikaVM.c
@@ -217,6 +217,10 @@ static Arg* VM_instruction_handler_OUT(PikaObj* self,
                                        char* data) {
     Arg* outArg = arg_copy(queue_popArg(vmState->q0));
     obj_setArg(vmState->locals, data, outArg);
+    if (TYPE_MATE_OBJECT == arg_getType(outArg)) {
+        /* init all object */
+        obj_getObj(self, data, 0);
+    }
     arg_deinit(outArg);
     return NULL;
 }