diff --git a/drivers/net/ethernet/nvidia/nvethernet/ether_linux.c b/drivers/net/ethernet/nvidia/nvethernet/ether_linux.c
index 23006a1f..40b86baa 100644
--- a/drivers/net/ethernet/nvidia/nvethernet/ether_linux.c
+++ b/drivers/net/ethernet/nvidia/nvethernet/ether_linux.c
@@ -2477,12 +2477,14 @@ static int ether_mdio_read(struct mii_bus *bus, int phyaddr, int phyreg)
 				(unsigned int)phyreg);
 }
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 3, 0)
+#if defined(NV_MII_BUS_STRUCT_HAS_WRITE_C45) /* Linux v6.3 */
 static int ether_mdio_write_c45(struct mii_bus *bus, int phyaddr, int devad, int regnum, u16 val)
 {
 	return ether_mdio_write(bus, phyaddr, ether_mdio_c45_addr(devad, regnum), val);
 }
+#endif
 
+#if defined(NV_MII_BUS_STRUCT_HAS_READ_C45) /* Linux v6.3 */
 static int ether_mdio_read_c45(struct mii_bus *bus, int phyaddr, int devad, int regnum)
 {
 	return ether_mdio_read(bus, phyaddr, ether_mdio_c45_addr(devad, regnum));
@@ -2521,8 +2523,10 @@ static int ether_mdio_register(struct ether_priv_data *pdata)
 	new_bus->name = "nvethernet_mdio_bus";
 	new_bus->read = ether_mdio_read;
 	new_bus->write = ether_mdio_write;
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 3, 0)
+#if defined(NV_MII_BUS_STRUCT_HAS_READ_C45) /* Linux v6.3 */
 	new_bus->read_c45 = ether_mdio_read_c45;
+#endif
+#if defined(NV_MII_BUS_STRUCT_HAS_WRITE_C45) /* Linux v6.3 */
 	new_bus->write_c45 = ether_mdio_write_c45;
 #endif
 	ret = snprintf(new_bus->id, MII_BUS_ID_SIZE, "%s", dev_name(dev));
diff --git a/scripts/conftest/Makefile b/scripts/conftest/Makefile
index 462c1a5a..c6ff7b07 100644
--- a/scripts/conftest/Makefile
+++ b/scripts/conftest/Makefile
@@ -116,6 +116,8 @@ NV_CONFTEST_FUNCTION_COMPILE_TESTS += get_user_pages
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += iio_dev_opaque_has_mlock
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += iommu_map_has_gfp_arg
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += kthread_complete_and_exit
+NV_CONFTEST_FUNCTION_COMPILE_TESTS += mii_bus_struct_has_read_c45
+NV_CONFTEST_FUNCTION_COMPILE_TESTS += mii_bus_struct_has_write_c45
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += netif_set_tso_max_size
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += netif_napi_add_weight
 NV_CONFTEST_FUNCTION_COMPILE_TESTS += pde_data
diff --git a/scripts/conftest/conftest.sh b/scripts/conftest/conftest.sh
index e686765c..fde017e8 100755
--- a/scripts/conftest/conftest.sh
+++ b/scripts/conftest/conftest.sh
@@ -6896,6 +6896,40 @@ compile_test() {
             compile_check_conftest "$CODE" "NV_KTHREAD_COMPLETE_AND_EXIT_PRESENT" "" "functions"
         ;;
 
+        mii_bus_struct_has_read_c45)
+            #
+            # Determine if the 'mii_bus' structure has 'read_c45' field.
+            #
+            # Added in commit 4e4aafcddbbf ("net: mdio: Add dedicated C45 API to
+            # MDIO bus drivers") in Linux v6.3.
+            #
+
+            CODE="
+            #include <linux/phy.h>
+            int conftest_mii_bus_struct_has_read_c45(void) {
+                return offsetof(struct mii_bus, read_c45);
+            }"
+
+            compile_check_conftest "$CODE" "NV_MII_BUS_STRUCT_HAS_READ_C45" "" "types"
+        ;;
+
+        mii_bus_struct_has_write_c45)
+            #
+            # Determine if the 'mii_bus' structure has 'write_c45' field.
+            #
+            # Added in commit 4e4aafcddbbf ("net: mdio: Add dedicated C45 API to
+            # MDIO bus drivers") in Linux v6.3.
+            #
+
+            CODE="
+            #include <linux/phy.h>
+            int conftest_mii_bus_struct_has_read_c45(void) {
+                return offsetof(struct mii_bus, write_c45);
+            }"
+
+            compile_check_conftest "$CODE" "NV_MII_BUS_STRUCT_HAS_WRITE_C45" "" "types"
+        ;;
+
         register_shrinker_has_fmt_arg)
             #
             # Determine if the 'register_shrinker' function