diff --git a/openpower/configs/openpower_p9_mambo_defconfig b/openpower/configs/openpower_p9_mambo_defconfig
index c86c3fd..8716c46 100644
--- a/openpower/configs/openpower_p9_mambo_defconfig
+++ b/openpower/configs/openpower_p9_mambo_defconfig
@@ -14,7 +14,7 @@
 BR2_ROOTFS_POST_BUILD_SCRIPT="../openpower/scripts/fixup-target-var"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_TARBALL=y
-BR2_LINUX_KERNEL_CUSTOM_TARBALL_LOCATION="https://cdn.kernel.org/pub/linux/kernel/v4.x/testing/linux-4.7-rc3.tar.xz"
+BR2_LINUX_KERNEL_CUSTOM_TARBALL_LOCATION="https://cdn.kernel.org/pub/linux/kernel/v4.x/testing/linux-4.8-rc5.tar.xz"
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="$(BR2_EXTERNAL)/configs/linux/skiroot_defconfig"
 BR2_LINUX_KERNEL_ZIMAGE_EPAPR=y
diff --git a/openpower/configs/witherspoon_defconfig b/openpower/configs/witherspoon_defconfig
index 214ca3d..e5eff9f 100644
--- a/openpower/configs/witherspoon_defconfig
+++ b/openpower/configs/witherspoon_defconfig
@@ -41,8 +41,8 @@
 BR2_ROOTFS_DEVICE_TABLE="../openpower/device_table.txt"
 BR2_ROOTFS_POST_BUILD_SCRIPT="../openpower/scripts/fixup-target-var"
 BR2_LINUX_KERNEL=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.4.18"
+BR2_LINUX_KERNEL_CUSTOM_TARBALL=y
+BR2_LINUX_KERNEL_CUSTOM_TARBALL_LOCATION="https://cdn.kernel.org/pub/linux/kernel/v4.x/testing/linux-4.8-rc5.tar.xz"
 BR2_KERNEL_HEADERS_4_4=y
 BR2_BINUTILS_VERSION_2_26_X=y
 BR2_LINUX_KERNEL_PATCH="$(BR2_EXTERNAL)/linux"