diff --git a/ports/atmel-samd/boards/hallowing_m4_express/mpconfigboard.h b/ports/atmel-samd/boards/hallowing_m4_express/mpconfigboard.h
index a0c726e726..38f78da4d3 100644
--- a/ports/atmel-samd/boards/hallowing_m4_express/mpconfigboard.h
+++ b/ports/atmel-samd/boards/hallowing_m4_express/mpconfigboard.h
@@ -23,8 +23,8 @@
 #define DEFAULT_SPI_BUS_MOSI (&pin_PB23)
 #define DEFAULT_SPI_BUS_MISO (&pin_PB22)
 
-#define DEFAULT_UART_BUS_RX (&pin_PB12)
-#define DEFAULT_UART_BUS_TX (&pin_PB13)
+#define DEFAULT_UART_BUS_RX (&pin_PB13)
+#define DEFAULT_UART_BUS_TX (&pin_PB12)
 
 // USB is always used internally so skip the pin objects for it.
 #define IGNORE_PIN_PA24     1