diff --git a/boards/calliope-mini/include/periph_conf.h b/boards/calliope-mini/include/periph_conf.h
index 5b4f1e59c9..3d77c88048 100644
--- a/boards/calliope-mini/include/periph_conf.h
+++ b/boards/calliope-mini/include/periph_conf.h
@@ -35,7 +35,6 @@ extern "C" {
  */
 #define UART_NUMOF          (1U)
 /* UART pin configuration */
-#define UART_HWFLOWCTRL     0
 #define UART_PIN_RX         25
 #define UART_PIN_TX         24
 /** @} */
diff --git a/boards/microbit/include/periph_conf.h b/boards/microbit/include/periph_conf.h
index 75fc502d9a..a5fac39602 100644
--- a/boards/microbit/include/periph_conf.h
+++ b/boards/microbit/include/periph_conf.h
@@ -34,7 +34,6 @@ extern "C" {
  */
 #define UART_NUMOF          (1U)
 /* UART pin configuration */
-#define UART_HWFLOWCTRL     0
 #define UART_PIN_RX         25
 #define UART_PIN_TX         24
 /** @} */
diff --git a/boards/nrf6310/include/periph_conf.h b/boards/nrf6310/include/periph_conf.h
index b154c8f927..9fd9236dfd 100644
--- a/boards/nrf6310/include/periph_conf.h
+++ b/boards/nrf6310/include/periph_conf.h
@@ -42,7 +42,6 @@ extern "C" {
 /* UART pin configuration */
 #define UART_PIN_RX       16
 #define UART_PIN_TX       17
-#define UART_HWFLOWCTRL   0
 #define UART_PIN_RTS      19
 #define UART_PIN_CTS      18
 /** @} */