diff --git a/arch/arm/cpu/armv7/ls102xa/fdt.c b/arch/arm/cpu/armv7/ls102xa/fdt.c
index 6c3caf8..8bf9c42 100644
--- a/arch/arm/cpu/armv7/ls102xa/fdt.c
+++ b/arch/arm/cpu/armv7/ls102xa/fdt.c
@@ -64,8 +64,8 @@
 		do_fixup_by_path(fdt, enet_path, "phy-connection-type",
 				 phy_string_for_interface(
 				 PHY_INTERFACE_MODE_RGMII_ID),
-				 sizeof(phy_string_for_interface(
-				 PHY_INTERFACE_MODE_RGMII_ID)),
+				 strlen(phy_string_for_interface(
+				 PHY_INTERFACE_MODE_RGMII_ID)) + 1,
 				 1);
 	}
 }