diff --git a/android/hal-msg.h b/android/hal-msg.h
index f19d0d0..1f77586 100644
--- a/android/hal-msg.h
+++ b/android/hal-msg.h
@@ -46,6 +46,8 @@ struct hal_msg_hdr {
 
 /* Core Service */
 
+#define HAL_ERROR_FAILED		0x01
+
 #define HAL_MSG_OP_ERROR		0x00
 struct hal_msg_rsp_error {
 	uint8_t status;
diff --git a/android/main.c b/android/main.c
index fe4f9de..aba7f66 100644
--- a/android/main.c
+++ b/android/main.c
@@ -70,7 +70,8 @@ static void service_register(void *buf, uint16_t len)
 	struct hal_msg_cmd_register_module *m = buf;
 
 	if (m->service_id > HAL_SERVICE_ID_MAX || services[m->service_id]) {
-		ipc_send_error(hal_cmd_io, HAL_SERVICE_ID_CORE, 0x01);
+		ipc_send_error(hal_cmd_io, HAL_SERVICE_ID_CORE,
+							HAL_ERROR_FAILED);
 		return;
 	}
 
@@ -87,7 +88,8 @@ static void service_unregister(void *buf, uint16_t len)
 	struct hal_msg_cmd_unregister_module *m = buf;
 
 	if (m->service_id > HAL_SERVICE_ID_MAX || !services[m->service_id]) {
-		ipc_send_error(hal_cmd_io, HAL_SERVICE_ID_CORE, 0x01);
+		ipc_send_error(hal_cmd_io, HAL_SERVICE_ID_CORE,
+							HAL_ERROR_FAILED);
 		return;
 	}
 
@@ -109,7 +111,8 @@ static void handle_service_core(uint8_t opcode, void *buf, uint16_t len)
 		service_unregister(buf, len);
 		break;
 	default:
-		ipc_send_error(hal_cmd_io, HAL_SERVICE_ID_CORE, 0x01);
+		ipc_send_error(hal_cmd_io, HAL_SERVICE_ID_CORE,
+							HAL_ERROR_FAILED);
 		break;
 	}
 }
@@ -151,7 +154,7 @@ static gboolean cmd_watch_cb(GIOChannel *io, GIOCondition cond,
 		handle_service_core(msg->opcode, buf + sizeof(*msg), msg->len);
 		break;
 	default:
-		ipc_send_error(hal_cmd_io, msg->service_id, 0x01);
+		ipc_send_error(hal_cmd_io, msg->service_id, HAL_ERROR_FAILED);
 		break;
 	}