diff --git a/tests/lpc18xx_43xx/test/host/cdc/test_cdc_rndis_host.c b/tests/lpc18xx_43xx/test/host/cdc/test_cdc_rndis_host.c
index 5805227d..be676652 100644
--- a/tests/lpc18xx_43xx/test/host/cdc/test_cdc_rndis_host.c
+++ b/tests/lpc18xx_43xx/test/host/cdc/test_cdc_rndis_host.c
@@ -104,16 +104,23 @@ rndis_msg_initialize_t msg_init =
     .max_xfer_size = 0x4000 // TODO mimic windows
 };
 
-//void test_rndis_send_initalize_failed(void)
-//{
-//
-//}
+void test_rndis_send_initalize_failed(void)
+{
+  usbh_control_xfer_subtask_ExpectWithArrayAndReturn(
+      dev_addr, 0x21, SEND_ENCAPSULATED_COMMAND, 0, p_comm_interface->bInterfaceNumber,
+      sizeof(rndis_msg_initialize_t), (uint8_t*)&msg_init, sizeof(rndis_msg_initialize_t), TUSB_ERROR_OSAL_TIMEOUT);
+
+  tusbh_cdc_mounted_cb_Expect(dev_addr);
+
+  //------------- Code Under Test -------------//
+  TEST_ASSERT_EQUAL( TUSB_ERROR_NONE, cdch_open_subtask(dev_addr, p_comm_interface, &length) );
+}
 
 void test_rndis_send_initalize_ok(void)
 {
   usbh_control_xfer_subtask_ExpectWithArrayAndReturn(
       dev_addr, 0x21, SEND_ENCAPSULATED_COMMAND, 0, p_comm_interface->bInterfaceNumber,
-      sizeof(rndis_msg_initialize_t), (uint8_t*)&msg_init, sizeof(rndis_msg_initialize_t), TUSB_ERROR_OSAL_TIMEOUT);
+      sizeof(rndis_msg_initialize_t), (uint8_t*)&msg_init, sizeof(rndis_msg_initialize_t), TUSB_ERROR_NONE);
 
 
   tusbh_cdc_rndis_mounted_cb_Expect(dev_addr);
diff --git a/tinyusb/class/cdc_host.c b/tinyusb/class/cdc_host.c
index 0e97c5d9..2b81b9ab 100644
--- a/tinyusb/class/cdc_host.c
+++ b/tinyusb/class/cdc_host.c
@@ -204,8 +204,8 @@ tusb_error_t cdch_open_subtask(uint8_t dev_addr, tusb_descriptor_interface_t con
   {
     OSAL_SUBTASK_INVOKED_AND_WAIT( rndish_open_subtask(dev_addr, p_cdc), error );
   }
-  else
-//  if ( TUSB_ERROR_NONE != error ) // device is not an rndis
+
+  if ( !(0xff == p_cdc->interface_protocol && TUSB_ERROR_NONE == error) ) // device is not an rndis
 #endif
 
   // FIXME mounted class flag is not set yet
diff --git a/tinyusb/class/cdc_rndis_host.c b/tinyusb/class/cdc_rndis_host.c
index 024329b4..585cf7d4 100644
--- a/tinyusb/class/cdc_rndis_host.c
+++ b/tinyusb/class/cdc_rndis_host.c
@@ -116,6 +116,11 @@ tusb_error_t rndish_open_subtask(uint8_t dev_addr, cdch_data_t *p_cdc)
     error
   );
 
+  if ( TUSB_ERROR_NONE != error)
+  {
+    SUBTASK_EXIT(error);
+  }
+
   if ( tusbh_cdc_rndis_mounted_cb )
   {
     tusbh_cdc_rndis_mounted_cb(dev_addr);