diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 971103714ddd..1166c52e51f4 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -618,7 +618,7 @@ static void uart_throttle(struct tty_struct *tty)
 {
 	struct uart_state *state = tty->driver_data;
 	struct uart_port *port = state->uart_port;
-	uint32_t mask = 0;
+	upf_t mask = 0;
 
 	if (I_IXOFF(tty))
 		mask |= UPF_SOFT_FLOW;
@@ -641,7 +641,7 @@ static void uart_unthrottle(struct tty_struct *tty)
 {
 	struct uart_state *state = tty->driver_data;
 	struct uart_port *port = state->uart_port;
-	uint32_t mask = 0;
+	upf_t mask = 0;
 
 	if (I_IXOFF(tty))
 		mask |= UPF_SOFT_FLOW;