diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index 9d1068d0489d..b62f88eec881 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -8,6 +8,7 @@
  */
 
 #include <linux/bits.h>
+#include <linux/kconfig.h>
 #include <linux/serial_8250.h>
 #include <linux/serial_core.h>
 #include <linux/dmaengine.h>
@@ -334,7 +335,7 @@ int fintek_8250_probe(struct uart_8250_port *uart);
 static inline int fintek_8250_probe(struct uart_8250_port *uart) { return 0; }
 #endif
 
-#ifdef CONFIG_SERIAL_8250_HUB6
+#if IS_REACHABLE(CONFIG_SERIAL_8250_HUB6)
 bool hub6_match_port(const struct uart_port *port1, const struct uart_port *port2);
 #else
 static inline bool hub6_match_port(const struct uart_port *port1, const struct uart_port *port2)