diff --git a/libraries/WiFi/src/ETH.cpp b/libraries/WiFi/src/ETH.cpp
index 092d6a3d467..cb5ad7a8c59 100644
--- a/libraries/WiFi/src/ETH.cpp
+++ b/libraries/WiFi/src/ETH.cpp
@@ -288,7 +288,12 @@ bool ETHClass::begin(uint8_t phy_addr, int power, int mdc, int mdio, eth_phy_typ
             break;
 #endif
         case ETH_PHY_KSZ8081:
+#if ESP_IDF_VERSION > ESP_IDF_VERSION_VAL(4,3,0)
             eth_phy = esp_eth_phy_new_ksz8081(&phy_config);
+#else
+            log_e("unsupported ethernet type 'ETH_PHY_KSZ8081'");
+#endif
+            break;
         default:
             break;
     }