diff --git a/targets/TARGET_NUVOTON/TARGET_M451/can_api.c b/targets/TARGET_NUVOTON/TARGET_M451/can_api.c
index f135575809..d569328675 100644
--- a/targets/TARGET_NUVOTON/TARGET_M451/can_api.c
+++ b/targets/TARGET_NUVOTON/TARGET_M451/can_api.c
@@ -130,8 +130,6 @@ static void can_irq(CANName name, int id)
         }
     } else if (u8IIDRstatus!=0) {
 
-        //CAN_MsgInterrupt(can, u8IIDRstatus);
-
         can0_irq_handler(can_irq_ids[id], IRQ_OVERRUN);
         
         CAN_CLR_INT_PENDING_BIT(can, ((can->IIDR) -1));      /* Clear Interrupt Pending */
@@ -168,19 +166,18 @@ void can_irq_set(can_t *obj, CanIrqType irq, uint32_t enable)
     
     CAN_EnterInitMode((CAN_T*)obj->can, ((enable != 0 )? CAN_CON_IE_Msk :0) );
     
-//    ((CAN_T *)(obj->can))->CON = (((CAN_T *)(obj->can))->CON ) | ((enable != 0 )? CAN_CON_IE_Msk :0);
     
     switch (irq)
     {
         case IRQ_ERROR:
-        //case IRQ_PASSIVE:
-        //case IRQ_ARB:
+        case IRQ_BUS:
+        case IRQ_PASSIVE:
             ((CAN_T *)(obj->can))->CON = (((CAN_T *)(obj->can))->CON) |CAN_CON_EIE_Msk;
+            ((CAN_T *)(obj->can))->CON = (((CAN_T *)(obj->can))->CON) |CAN_CON_SIE_Msk;
             break;
         
         case IRQ_RX:
         case IRQ_TX:
-        case IRQ_BUS:
         case IRQ_OVERRUN:
         case IRQ_WAKEUP:
             ((CAN_T *)(obj->can))->CON = (((CAN_T *)(obj->can))->CON) |CAN_CON_SIE_Msk;
diff --git a/targets/TARGET_NUVOTON/TARGET_NUC472/can_api.c b/targets/TARGET_NUVOTON/TARGET_NUC472/can_api.c
index 923dcd6243..6d13fe09f8 100644
--- a/targets/TARGET_NUVOTON/TARGET_NUC472/can_api.c
+++ b/targets/TARGET_NUVOTON/TARGET_NUC472/can_api.c
@@ -149,7 +149,6 @@ static void can_irq(CANName name, int id)
         }
     } else if (u8IIDRstatus!=0) {
 
-        //CAN_MsgInterrupt(can, u8IIDRstatus);
         if(id)
             can1_irq_handler(can_irq_ids[id] , IRQ_OVERRUN);
         else
@@ -211,14 +210,14 @@ void can_irq_set(can_t *obj, CanIrqType irq, uint32_t enable)
     switch (irq)
     {
         case IRQ_ERROR:
-        //case IRQ_PASSIVE:
-        //case IRQ_ARB:
+        case IRQ_BUS:
+        case IRQ_PASSIVE:
             ((CAN_T *)(obj->can))->CON = (((CAN_T *)(obj->can))->CON) |CAN_CON_EIE_Msk;
+            ((CAN_T *)(obj->can))->CON = (((CAN_T *)(obj->can))->CON) |CAN_CON_SIE_Msk;
             break;
         
         case IRQ_RX:
         case IRQ_TX:
-        case IRQ_BUS:
         case IRQ_OVERRUN:
         case IRQ_WAKEUP:
             ((CAN_T *)(obj->can))->CON = (((CAN_T *)(obj->can))->CON) |CAN_CON_SIE_Msk;