diff --git a/targets/TARGET_NUVOTON/TARGET_M451/can_api.c b/targets/TARGET_NUVOTON/TARGET_M451/can_api.c
index 5c4e0f34bc8..d8254406de8 100644
--- a/targets/TARGET_NUVOTON/TARGET_M451/can_api.c
+++ b/targets/TARGET_NUVOTON/TARGET_M451/can_api.c
@@ -314,10 +314,6 @@ int can_filter(can_t *obj, uint32_t id, uint32_t mask, CANFormat format, int32_t
     }
 
     uint32_t numask = mask;
-    if( numask == 0x0000 )
-    {
-      return CAN_SetRxMsg((CAN_T *)NU_MODBASE(obj->can), handle, (uint32_t)format, id);
-    }
     if( format == CANStandard )
     {
       numask = (mask << 18);
diff --git a/targets/TARGET_NUVOTON/TARGET_M480/can_api.c b/targets/TARGET_NUVOTON/TARGET_M480/can_api.c
index 4312ff12053..c4910180c5e 100644
--- a/targets/TARGET_NUVOTON/TARGET_M480/can_api.c
+++ b/targets/TARGET_NUVOTON/TARGET_M480/can_api.c
@@ -363,10 +363,6 @@ int can_filter(can_t *obj, uint32_t id, uint32_t mask, CANFormat format, int32_t
     }
 
     uint32_t numask = mask;
-    if( numask == 0x0000 )
-    {
-      return CAN_SetRxMsg((CAN_T *)NU_MODBASE(obj->can), handle, (uint32_t)format, id);
-    }
     if( format == CANStandard )
     {
       numask = (mask << 18);