diff --git a/configs/rock5b_defconfig b/configs/rock5b_defconfig
index 899537c001..e3c4414948 100644
--- a/configs/rock5b_defconfig
+++ b/configs/rock5b_defconfig
@@ -46,6 +46,7 @@ BR2_PACKAGE_HOST_DOSFSTOOLS=y
 BR2_PACKAGE_HOST_DTC=y
 BR2_PACKAGE_HOST_GENIMAGE=y
 BR2_PACKAGE_HOST_MTOOLS=y
+BR2_SYSTEM_DHCP="eth0"
 BR2_ROOTFS_POST_BUILD_SCRIPT="board/radxa/rock5b/post-build.sh"
 BR2_ROOTFS_POST_IMAGE_SCRIPT="support/scripts/genimage.sh"
 BR2_ROOTFS_POST_SCRIPT_ARGS="-c board/radxa/rock5b/genimage.cfg"