diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 89f7b6c63598..536b2581d3e2 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -852,9 +852,9 @@ static inline unsigned long uart_fifo_timeout(struct uart_port *port)
 }
 
 /* Base timer interval for polling */
-static inline int uart_poll_timeout(struct uart_port *port)
+static inline unsigned long uart_poll_timeout(struct uart_port *port)
 {
-	int timeout = uart_fifo_timeout(port);
+	unsigned long timeout = uart_fifo_timeout(port);
 
 	return timeout > 6 ? (timeout / 2 - 2) : 1;
 }