diff --git a/targets/TARGET_NUVOTON/TARGET_M451/can_api.c b/targets/TARGET_NUVOTON/TARGET_M451/can_api.c
index fa2e7c2e21..678de11109 100644
--- a/targets/TARGET_NUVOTON/TARGET_M451/can_api.c
+++ b/targets/TARGET_NUVOTON/TARGET_M451/can_api.c
@@ -294,7 +294,7 @@ int can_filter(can_t *obj, uint32_t id, uint32_t mask, CANFormat format, int32_t
     {
       numask = (mask << 18);
     }
-    numask = (numask | CAN_IF_MASK2_MDIR_Msk | CAN_IF_MASK2_MXTD_Msk);
+    numask = (numask | ((CAN_IF_MASK2_MDIR_Msk | CAN_IF_MASK2_MXTD_Msk) << 16));
     return CAN_SetRxMsgAndMsk((CAN_T *)NU_MODBASE(obj->can), handle, (uint32_t)format, id, numask);
 }
 
diff --git a/targets/TARGET_NUVOTON/TARGET_M480/can_api.c b/targets/TARGET_NUVOTON/TARGET_M480/can_api.c
index 771cb6d9ff..00a840b98f 100644
--- a/targets/TARGET_NUVOTON/TARGET_M480/can_api.c
+++ b/targets/TARGET_NUVOTON/TARGET_M480/can_api.c
@@ -341,7 +341,7 @@ int can_filter(can_t *obj, uint32_t id, uint32_t mask, CANFormat format, int32_t
     {
       numask = (mask << 18);
     }
-    numask = (numask | CAN_IF_MASK2_MDIR_Msk | CAN_IF_MASK2_MXTD_Msk);
+    numask = (numask | ((CAN_IF_MASK2_MDIR_Msk | CAN_IF_MASK2_MXTD_Msk) << 16));
     return CAN_SetRxMsgAndMsk((CAN_T *)NU_MODBASE(obj->can), handle, (uint32_t)format, id, numask);
 }