diff --git a/boards/arduino/giga_r1/arduino_giga_r1_stm32h747xx_m7.dts b/boards/arduino/giga_r1/arduino_giga_r1_stm32h747xx_m7.dts
index f5520ae8f2266..662f20d357156 100644
--- a/boards/arduino/giga_r1/arduino_giga_r1_stm32h747xx_m7.dts
+++ b/boards/arduino/giga_r1/arduino_giga_r1_stm32h747xx_m7.dts
@@ -76,6 +76,10 @@
 	clock-frequency = <DT_FREQ_M(480)>;
 };
 
+&usart1_rx_pb7 {
+	bias-pull-up;
+};
+
 &usart1 {
 	status = "okay";
 	pinctrl-0 = <&usart1_tx_pa9 &usart1_rx_pb7>;
@@ -83,6 +87,10 @@
 	current-speed = <115200>;
 };
 
+&usart6_rx_pc7 {
+	bias-pull-up;
+};
+
 &usart6 {
 	status = "disabled";
 	pinctrl-0 = <&usart6_tx_pg14 &usart6_rx_pc7>;
@@ -90,6 +98,10 @@
 	current-speed = <115200>;
 };
 
+&uart4_rx_pi9 {
+	bias-pull-up;
+};
+
 &uart4 {
 	status = "disabled";
 	pinctrl-0 = <&uart4_tx_ph13 &uart4_rx_pi9>;
diff --git a/boards/arduino/opta/arduino_opta-common.dtsi b/boards/arduino/opta/arduino_opta-common.dtsi
index afb351894373e..fb8d959c4e2de 100644
--- a/boards/arduino/opta/arduino_opta-common.dtsi
+++ b/boards/arduino/opta/arduino_opta-common.dtsi
@@ -104,6 +104,16 @@
 	};
 };
 
+&usart6_rx_pg9 {
+	bias-pull-up;
+};
+
+&usart6 {
+	pinctrl-0 = <&usart6_tx_pg14 &usart6_rx_pg9>;
+	pinctrl-names = "default";
+	current-speed = <115200>;
+};
+
 &adc1 {
 	pinctrl-0 = <&adc1_inp0_pa0_c &adc1_inp6_pf12>;
 	pinctrl-names = "default";
diff --git a/boards/arduino/portenta_h7/arduino_portenta_h7-common.dtsi b/boards/arduino/portenta_h7/arduino_portenta_h7-common.dtsi
index 3da3ac9badb2f..d8d73603b934e 100644
--- a/boards/arduino/portenta_h7/arduino_portenta_h7-common.dtsi
+++ b/boards/arduino/portenta_h7/arduino_portenta_h7-common.dtsi
@@ -49,6 +49,10 @@
 };
 
 /* UART0 in datasheet */
+&uart4_rx_pi9 {
+	bias-pull-up;
+};
+
 &uart4 {
 	pinctrl-0 = <&uart4_tx_pa0 &uart4_rx_pi9>;
 	pinctrl-names = "default";
@@ -56,6 +60,10 @@
 };
 
 /* UART1 in datasheet */
+&usart1_rx_pa10 {
+	bias-pull-up;
+};
+
 &usart1 {
 	pinctrl-0 = <&usart1_tx_pa9 &usart1_rx_pa10>;
 	pinctrl-names = "default";
@@ -63,6 +71,10 @@
 };
 
 /* UART2 in datasheet */
+&usart6_rx_pg9 {
+	bias-pull-up;
+};
+
 &usart6 {
 	pinctrl-0 = <&usart6_tx_pg14 &usart6_rx_pg9>;
 	pinctrl-names = "default";
@@ -70,6 +82,10 @@
 };
 
 /* UART3 in datasheet */
+&uart8_rx_pj9 {
+	bias-pull-up;
+};
+
 &uart8 {
 	pinctrl-0 = <&uart8_tx_pj8 &uart8_rx_pj9>;
 	pinctrl-names = "default";
diff --git a/boards/arduino/uno_q/arduino_uno_q-common.dtsi b/boards/arduino/uno_q/arduino_uno_q-common.dtsi
index 9410188d15ca6..a0529c2ac9700 100644
--- a/boards/arduino/uno_q/arduino_uno_q-common.dtsi
+++ b/boards/arduino/uno_q/arduino_uno_q-common.dtsi
@@ -98,14 +98,22 @@ stm32_lp_tick_source: &lptim1 {
 	status = "okay";
 };
 
+&lpuart1_rx_pg8 {
+	bias-pull-up;
+};
+
 &lpuart1 {
 	pinctrl-0 = <&lpuart1_tx_pg7 &lpuart1_rx_pg8
-				&lpuart1_rts_pg6 &lpuart1_cts_pg5>;
+		     &lpuart1_rts_pg6 &lpuart1_cts_pg5>;
 	pinctrl-names = "default";
 	current-speed = <115200>;
 	status = "okay";
 };
 
+&usart1_rx_pb7 {
+	bias-pull-up;
+};
+
 &usart1 {
 	status = "okay";
 	pinctrl-0 = <&usart1_tx_pb6 &usart1_rx_pb7>;
@@ -245,4 +253,4 @@ zephyr_udc0: &usbotg_fs {
 
 &gpiog {
 	status = "okay";
-};
\ No newline at end of file
+};