diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
index e051e1b57609..de68707a99c7 100644
--- a/drivers/of/of_mdio.c
+++ b/drivers/of/of_mdio.c
@@ -361,7 +361,7 @@ struct phy_device *of_phy_attach(struct net_device *dev,
 }
 EXPORT_SYMBOL(of_phy_attach);
 
-#if defined(CONFIG_FIXED_PHY)
+#if IS_ENABLED(CONFIG_FIXED_PHY)
 /*
  * of_phy_is_fixed_link() and of_phy_register_fixed_link() must
  * support two DT bindings:
diff --git a/include/linux/of_mdio.h b/include/linux/of_mdio.h
index 8f2237eb3485..6c8cb9aa4c00 100644
--- a/include/linux/of_mdio.h
+++ b/include/linux/of_mdio.h
@@ -69,7 +69,7 @@ static inline int of_mdio_parse_addr(struct device *dev,
 }
 #endif /* CONFIG_OF */
 
-#if defined(CONFIG_OF) && defined(CONFIG_FIXED_PHY)
+#if defined(CONFIG_OF) && IS_ENABLED(CONFIG_FIXED_PHY)
 extern int of_phy_register_fixed_link(struct device_node *np);
 extern bool of_phy_is_fixed_link(struct device_node *np);
 #else