diff --git a/targets/TARGET_NUVOTON/TARGET_M2351/PeripheralNames.h b/targets/TARGET_NUVOTON/TARGET_M2351/PeripheralNames.h
index d5ce69b3d4..e56c403a12 100644
--- a/targets/TARGET_NUVOTON/TARGET_M2351/PeripheralNames.h
+++ b/targets/TARGET_NUVOTON/TARGET_M2351/PeripheralNames.h
@@ -163,7 +163,7 @@ typedef enum {
 #endif
 
     // NOTE: board-specific
-    STDIO_UART  = UART_3
+    STDIO_UART  = UART_0
 
 } UARTName;