diff --git a/boards/st/stm32h745i_disco/Kconfig.defconfig b/boards/st/stm32h745i_disco/Kconfig.defconfig
index f2830611565..1788447e060 100644
--- a/boards/st/stm32h745i_disco/Kconfig.defconfig
+++ b/boards/st/stm32h745i_disco/Kconfig.defconfig
@@ -14,6 +14,10 @@ config NET_L2_ETHERNET
 config ETH_STM32_HAL_MII
 	default y
 
+# STM32H745I-DISCO have PHY connected to address 1
+config ETH_STM32_HAL_PHY_ADDRESS
+	default 1
+
 endif # NETWORKING
 
 config MEMC
diff --git a/boards/st/stm32h745i_disco/stm32h745i_disco_stm32h745xx_m7.dts b/boards/st/stm32h745i_disco/stm32h745i_disco_stm32h745xx_m7.dts
index fbc3a388b9c..f1e7204a864 100644
--- a/boards/st/stm32h745i_disco/stm32h745i_disco_stm32h745xx_m7.dts
+++ b/boards/st/stm32h745i_disco/stm32h745i_disco_stm32h745xx_m7.dts
@@ -151,9 +151,9 @@
 	pinctrl-0 = <&eth_mdio_pa2 &eth_mdc_pc1>;
 	pinctrl-names = "default";
 
-	ethernet-phy@0 {
+	ethernet-phy@1 {
 		compatible = "ethernet-phy";
-		reg = <0x00>;
+		reg = <0x01>;
 		status = "okay";
 	};
 };