diff --git a/sys/can/device.c b/sys/can/device.c
index 8f81a2a85ca3376d7021c3c7f13ceb129f8e713a..24d291e32239b15b8dc9b8586e31a525697caa9b 100644
--- a/sys/can/device.c
+++ b/sys/can/device.c
@@ -49,24 +49,6 @@ static void pm_cb(void *arg);
 static void pm_reset(candev_dev_t *candev_dev, uint32_t value);
 #endif
 
-static inline enum can_msg _can_event_error_to_msg(candev_event_t error)
-{
-    switch (error) {
-    case CANDEV_EVENT_TX_ERROR:
-        return CAN_MSG_TX_ERROR;
-    case CANDEV_EVENT_RX_ERROR:
-        return CAN_MSG_RX_ERROR;
-    case CANDEV_EVENT_BUS_OFF:
-        return CAN_MSG_BUS_OFF;
-    case CANDEV_EVENT_ERROR_PASSIVE:
-        return CAN_MSG_ERROR_PASSIVE;
-    case CANDEV_EVENT_ERROR_WARNING:
-        return CAN_MSG_ERROR_WARNING;
-    default:
-        return 0;
-    }
-}
-
 static void _can_event(candev_t *dev, candev_event_t event, void *arg)
 {
     msg_t msg;
diff --git a/sys/include/can/device.h b/sys/include/can/device.h
index 00c7e2b1174981048ff0c49896f0417abd405d38..7a484ae03f32d0a343facdc01d5763ee02dcf40f 100644
--- a/sys/include/can/device.h
+++ b/sys/include/can/device.h
@@ -46,7 +46,7 @@ extern "C" {
 /**
  * Maximum number of interfaces which can be registered on DLL
  */
-#define CAN_DLL_NUMOF       (1U)
+#define CAN_DLL_NUMOF       (1)
 #endif
 
 /**