diff --git a/atmel-samd/boards/arduino_zero/conf_board.h b/atmel-samd/boards/arduino_zero/conf_board.h
index ea9327571b..7b88c97fc2 100644
--- a/atmel-samd/boards/arduino_zero/conf_board.h
+++ b/atmel-samd/boards/arduino_zero/conf_board.h
@@ -11,12 +11,4 @@
 #ifndef CONF_BOARD_H
 #define CONF_BOARD_H
 
-#define EDBG_CDC_SERCOM_MUX_SETTING  USART_RX_3_TX_2_XCK_3
-#define EDBG_CDC_SERCOM_PINMUX_PAD0  PINMUX_UNUSED
-#define EDBG_CDC_SERCOM_PINMUX_PAD1  PINMUX_UNUSED
-#define EDBG_CDC_SERCOM_PINMUX_PAD2  PINMUX_PB22D_SERCOM5_PAD2
-#define EDBG_CDC_SERCOM_PINMUX_PAD3  PINMUX_PB23D_SERCOM5_PAD3
-
-#define EDBG_CDC_MODULE              SERCOM5
-
 #endif // CONF_BOARD_H
diff --git a/atmel-samd/boards/arduino_zero/init.c b/atmel-samd/boards/arduino_zero/init.c
index 6ec302e6f7..72a051aec1 100644
--- a/atmel-samd/boards/arduino_zero/init.c
+++ b/atmel-samd/boards/arduino_zero/init.c
@@ -14,26 +14,6 @@
 #include "asf/sam0/drivers/sercom/usart/usart.h"
 #include "asf/sam0/drivers/port/port.h"
 
-extern struct usart_module usart_instance;
-
-void configure_usart(void)
-{
-    struct usart_config config_usart;
-
-    usart_get_config_defaults(&config_usart);
-
-    config_usart.baudrate    = 115200;
-    config_usart.mux_setting = EDBG_CDC_SERCOM_MUX_SETTING;
-    config_usart.pinmux_pad0 = EDBG_CDC_SERCOM_PINMUX_PAD0;
-    config_usart.pinmux_pad1 = EDBG_CDC_SERCOM_PINMUX_PAD1;
-    config_usart.pinmux_pad2 = EDBG_CDC_SERCOM_PINMUX_PAD2;
-    config_usart.pinmux_pad3 = EDBG_CDC_SERCOM_PINMUX_PAD3;
-
-    while (usart_init(&usart_instance, EDBG_CDC_MODULE, &config_usart) != STATUS_OK) {
-    }
-    usart_enable(&usart_instance);
-}
-
 void board_init(void)
 {
     /* This function is meant to contain board-specific initialization code
@@ -49,9 +29,4 @@ void board_init(void)
 
     port_pin_set_config(MICROPY_HW_LED_RX, &pin_conf);
     port_pin_set_output_level(MICROPY_HW_LED_RX, true);
-
-    // TODO(tannewt): Switch to proper pyb based UARTs.
-    #ifdef UART_REPL
-        configure_usart();
-    #endif
 }