diff --git a/configs/saml21-xplained/include/board.h b/configs/saml21-xplained/include/board.h
index d3a63c44f2..3636e62c5d 100644
--- a/configs/saml21-xplained/include/board.h
+++ b/configs/saml21-xplained/include/board.h
@@ -425,7 +425,7 @@
  */
 
 #define BOARD_SERCOM3_GCLKGEN        GCLK_CLKCTRL_GEN0
-#define BOARD_SERCOM3_MUXCONFIG      (USART_CTRLA_RXPAD1 | USART_CTRLA_TXPAD0_1)
+#define BOARD_SERCOM3_MUXCONFIG      (USART_CTRLA_RXPAD1 | USART_CTRLA_TXPAD0_2)
 #define BOARD_SERCOM3_PINMAP_PAD0    PORT_SERCOM3_PAD0_1 /* USART TX */
 #define BOARD_SERCOM3_PINMAP_PAD1    PORT_SERCOM3_PAD1_1 /* USART RX */
 #define BOARD_SERCOM3_PINMAP_PAD2    0                   /* (not used) */
@@ -445,7 +445,7 @@
 
 #define BOARD_SERCOM4_GCLKGEN        GCLK_CLKCTRL_GEN0
 
-#define BOARD_SERCOM4_MUXCONFIG    (USART_CTRLA_RXPAD1 | USART_CTRLA_TXPAD0)
+#define BOARD_SERCOM4_MUXCONFIG    (USART_CTRLA_RXPAD1 | USART_CTRLA_TXPAD0_2)
 #define BOARD_SERCOM4_PINMAP_PAD0  PORT_SERCOM4_PAD0_3 /* USART TX */
 #define BOARD_SERCOM4_PINMAP_PAD1  PORT_SERCOM4_PAD1_3 /* USART RX */
 #define BOARD_SERCOM4_PINMAP_PAD2  0