diff --git a/sys/dev/fxp/if_fxp.c b/sys/dev/fxp/if_fxp.c
index 7d482c90538e..70dc1848014a 100644
--- a/sys/dev/fxp/if_fxp.c
+++ b/sys/dev/fxp/if_fxp.c
@@ -452,8 +452,8 @@ fxp_attach(device_t dev)
 	 * Determine whether we must use the 503 serial interface.
 	 */
 	fxp_read_eeprom(sc, &data, 6, 1);
-	if ((data & FXP_PHY_DEVICE_MASK) != 0 &&
-	    (data & FXP_PHY_SERIAL_ONLY))
+	if (sc->revision == FXP_REV_82557 && (data & FXP_PHY_DEVICE_MASK) != 0
+	    && (data & FXP_PHY_SERIAL_ONLY))
 		sc->flags |= FXP_FLAG_SERIAL_MEDIA;
 
 	SYSCTL_ADD_PROC(device_get_sysctl_ctx(dev),