diff --git a/phy.h b/phy.h
index 749cfb1..38c7f4c 100644
--- a/phy.h
+++ b/phy.h
@@ -21,6 +21,7 @@
  */
 #define PHY_ANEG_CTRL		0x00
 #define PHY_ANEG_ADV		0x10
+#define PHY_ANEG_LP_ABILITY	0x13
 #define PHY_ANEG_MGBASE_CTRL 0x20
 #define PHY_EEE_ADV		0x3c
 #define PHY_EEE_LP_ABILITY	0x3d
diff --git a/rtl837x_phy.c b/rtl837x_phy.c
index 1adfa0f..63fffbc 100644
--- a/rtl837x_phy.c
+++ b/rtl837x_phy.c
@@ -393,7 +393,7 @@ void phy_show(uint8_t port) __banked
 		if (v & 0x0080)
 			print_string(" 2500BaseN-Full");
 	}
-	phy_read(port, PHY_MMD_AN, 0x13);
+	phy_read(port, PHY_MMD_AN, PHY_ANEG_LP_ABILITY);
 	v = SFR_DATA_U16;
 	print_string("\nLink Partner advertises:");
 	if (v & 0x0020)