diff --git a/locale/circuitpython.pot b/locale/circuitpython.pot
index 72ee60cc0c..24b5b541dc 100644
--- a/locale/circuitpython.pot
+++ b/locale/circuitpython.pot
@@ -1987,10 +1987,6 @@ msgstr ""
 msgid "Stopping AP is not supported."
 msgstr ""
 
-#: ports/mimxrt10xx/common-hal/busio/UART.c ports/stm/common-hal/busio/UART.c
-msgid "Supply at least one UART pin"
-msgstr ""
-
 #: shared-bindings/alarm/time/TimeAlarm.c
 msgid "Supply one of monotonic_time or epoch_time"
 msgstr ""
@@ -4116,8 +4112,6 @@ msgstr ""
 msgid "twai_start returned esp-idf error #%d"
 msgstr ""
 
-#: ports/atmel-samd/common-hal/busio/UART.c
-#: ports/espressif/common-hal/busio/UART.c ports/nrf/common-hal/busio/UART.c
 #: shared-bindings/busio/UART.c shared-bindings/canio/CAN.c
 msgid "tx and rx cannot both be None"
 msgstr ""
diff --git a/ports/espressif/common-hal/busio/UART.c b/ports/espressif/common-hal/busio/UART.c
index f025c15b3e..c13bdedac0 100644
--- a/ports/espressif/common-hal/busio/UART.c
+++ b/ports/espressif/common-hal/busio/UART.c
@@ -112,9 +112,8 @@ void common_hal_busio_uart_construct(busio_uart_obj_t *self,
 
     uart_config_t uart_config = {0};
     bool have_rs485_dir = rs485_dir != NULL;
-    if (!have_tx && !have_rx) {
-        mp_raise_ValueError(translate("tx and rx cannot both be None"));
-    }
+
+    // shared-bindings checks that TX and RX are not both None, so we don't need to check here.
 
     // Filter for sane settings for RS485
     if (have_rs485_dir) {
diff --git a/ports/mimxrt10xx/common-hal/busio/UART.c b/ports/mimxrt10xx/common-hal/busio/UART.c
index a61b86bee3..086b8dee87 100644
--- a/ports/mimxrt10xx/common-hal/busio/UART.c
+++ b/ports/mimxrt10xx/common-hal/busio/UART.c
@@ -179,7 +179,8 @@ void common_hal_busio_uart_construct(busio_uart_obj_t *self,
             break;
         }
     } else {
-        mp_raise_ValueError(translate("tx and rx cannot both be None"));
+        // TX and RX are both None. But this is already handled in shared-bindings, so
+        // we won't get here.
     }
 
     if (rx && !rx_config) {
diff --git a/ports/nrf/common-hal/busio/UART.c b/ports/nrf/common-hal/busio/UART.c
index df4a485999..10a34e09df 100644
--- a/ports/nrf/common-hal/busio/UART.c
+++ b/ports/nrf/common-hal/busio/UART.c
@@ -183,9 +183,7 @@ void common_hal_busio_uart_construct(busio_uart_obj_t *self,
         mp_raise_ValueError(translate("All UART peripherals are in use"));
     }
 
-    if ((tx == NULL) && (rx == NULL)) {
-        mp_raise_ValueError(translate("tx and rx cannot both be None"));
-    }
+    // shared-bindings checks that TX and RX are not both None, so we don't need to check here.
 
     mp_arg_validate_int_min(receiver_buffer_size, 1, MP_QSTR_receiver_buffer_size);
 
diff --git a/ports/stm/common-hal/busio/UART.c b/ports/stm/common-hal/busio/UART.c
index e8284713d1..cdace31639 100644
--- a/ports/stm/common-hal/busio/UART.c
+++ b/ports/stm/common-hal/busio/UART.c
@@ -85,7 +85,7 @@ void common_hal_busio_uart_construct(busio_uart_obj_t *self,
     bool sigint_enabled) {
 
     // match pins to UART objects
-    USART_TypeDef *USARTx;
+    USART_TypeDef *USARTx = NULL;
 
     uint8_t tx_len = MP_ARRAY_SIZE(mcu_uart_tx_list);
     uint8_t rx_len = MP_ARRAY_SIZE(mcu_uart_rx_list);
@@ -159,8 +159,8 @@ void common_hal_busio_uart_construct(busio_uart_obj_t *self,
         USARTx = assign_uart_or_throw(self, (self->tx != NULL),
             periph_index, uart_taken);
     } else {
-        // both pins cannot be empty
-        mp_raise_ValueError(translate("tx and rx cannot both be None"));
+        // TX and RX are both None. But this is already handled in shared-bindings, so
+        // we won't get here.
     }
 
     // Other errors