diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index d1c5e536a167..143300a80090 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -129,9 +129,13 @@ static int stm32_config_rs485(struct uart_port *port,
 		if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
 			cr3 &= ~USART_CR3_DEP;
 			rs485conf->flags &= ~SER_RS485_RTS_AFTER_SEND;
+			mctrl_gpio_set(stm32_port->gpios,
+					stm32_port->port.mctrl & ~TIOCM_RTS);
 		} else {
 			cr3 |= USART_CR3_DEP;
 			rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
+			mctrl_gpio_set(stm32_port->gpios,
+					stm32_port->port.mctrl | TIOCM_RTS);
 		}
 
 		writel_relaxed(cr3, port->membase + ofs->cr3);
@@ -847,9 +851,13 @@ static void stm32_set_termios(struct uart_port *port, struct ktermios *termios,
 		if (rs485conf->flags & SER_RS485_RTS_ON_SEND) {
 			cr3 &= ~USART_CR3_DEP;
 			rs485conf->flags &= ~SER_RS485_RTS_AFTER_SEND;
+			mctrl_gpio_set(stm32_port->gpios,
+					stm32_port->port.mctrl & ~TIOCM_RTS);
 		} else {
 			cr3 |= USART_CR3_DEP;
 			rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
+			mctrl_gpio_set(stm32_port->gpios,
+					stm32_port->port.mctrl | TIOCM_RTS);
 		}
 
 	} else {