diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c
index b6b7ea6b5b82..10704522c353 100644
--- a/drivers/tty/serdev/serdev-ttyport.c
+++ b/drivers/tty/serdev/serdev-ttyport.c
@@ -301,12 +301,16 @@ struct device *serdev_tty_port_register(struct tty_port *port,
 	 * be ignored.
 	 */
 	if (parent->bus == &platform_bus_type) {
-		char tty_port_name[7];
+		if (pdev_tty_port) {
+			unsigned long pdev_idx;
+			int tty_len = strlen(drv->name);
 
-		sprintf(tty_port_name, "%s%d", drv->name, idx);
-		if (pdev_tty_port &&
-		    !strcmp(pdev_tty_port, tty_port_name)) {
-			platform = true;
+			if (!strncmp(pdev_tty_port, drv->name, tty_len)) {
+				if (!kstrtoul(pdev_tty_port + tty_len, 10,
+					     &pdev_idx) && pdev_idx == idx) {
+					platform = true;
+				}
+			}
 		}
 	}