diff --git a/target/linux/realtek/files-6.18/drivers/net/mdio/mdio-realtek-otto.c b/target/linux/realtek/files-6.18/drivers/net/mdio/mdio-realtek-otto.c
index dbad948455..9979b8a449 100644
--- a/target/linux/realtek/files-6.18/drivers/net/mdio/mdio-realtek-otto.c
+++ b/target/linux/realtek/files-6.18/drivers/net/mdio/mdio-realtek-otto.c
@@ -124,7 +124,7 @@
 #define RTMDIO_931X_SMI_10GPHY_POLLING_SEL4	(0x0D00)
 
 #define for_each_port(ctrl, pn) \
-	for_each_set_bit(pn, ctrl->valid_ports, RTMDIO_MAX_PORTS)
+	for_each_set_bit(pn, (ctrl)->valid_ports, RTMDIO_MAX_PORTS)
 
 /*
  * On all Realtek switch platforms the hardware periodically reads the link status of all