diff --git a/sdk_container/src/third_party/coreos-overlay/sys-fs/btrfs-progs/README.md b/sdk_container/src/third_party/coreos-overlay/sys-fs/btrfs-progs/README.md
new file mode 100644
index 0000000000..d3ed623221
--- /dev/null
+++ b/sdk_container/src/third_party/coreos-overlay/sys-fs/btrfs-progs/README.md
@@ -0,0 +1,14 @@
+We forked this package for the following reasons:
+
+- We override the udev rules directory. The configure script does not
+  provide a way to override it, so we need to hack it, otherwise the
+  configure script will figure out the wrong path in our builds. We do
+  it by overriding it in Makefile.inc.in. Ideal solution here would be
+  to patch btrfs-progs to allow overriding the udev path and then
+  override it in the ebuild properly, without the sed hacks.
+
+- We change the python versions, because we still have only python
+  3.6.
+
+- We stabilize the package on both amd64 and arm64 to keep it in sync
+  with our linux kernel version.
diff --git a/sdk_container/src/third_party/coreos-overlay/sys-fs/btrfs-progs/btrfs-progs-5.15.1.ebuild b/sdk_container/src/third_party/coreos-overlay/sys-fs/btrfs-progs/btrfs-progs-5.15.1.ebuild
index 36548f98db..73f71df572 100644
--- a/sdk_container/src/third_party/coreos-overlay/sys-fs/btrfs-progs/btrfs-progs-5.15.1.ebuild
+++ b/sdk_container/src/third_party/coreos-overlay/sys-fs/btrfs-progs/btrfs-progs-5.15.1.ebuild
@@ -3,16 +3,19 @@
 
 EAPI=7
 
-PYTHON_COMPAT=( python3_{8..9} )
+# Flatcar: We still have python 3.6 only.
+PYTHON_COMPAT=( python3_{6..9} )
 
-inherit bash-completion-r1 python-single-r1
+# Flatcar: Inherit udev eclass, so we can get the udev directory.
+inherit bash-completion-r1 python-single-r1 udev
 
 libbtrfs_soname=0
 
 if [[ ${PV} != 9999 ]]; then
 	MY_PV="v${PV/_/-}"
 	[[ "${PV}" = *_rc* ]] || \
-	KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~ia64 ~mips ~ppc ~ppc64 ~riscv ~sparc ~x86"
+	# Flatcar: Stabilize our arches.
+	KEYWORDS="~alpha amd64 ~arm arm64 ~ia64 ~mips ~ppc ~ppc64 ~riscv ~sparc ~x86"
 	SRC_URI="https://www.kernel.org/pub/linux/kernel/people/kdave/${PN}/${PN}-${MY_PV}.tar.xz"
 	S="${WORKDIR}/${PN}-${MY_PV}"
 else
@@ -94,6 +97,8 @@ src_prepare() {
 		ln -s "${EPREFIX}"/usr/share/gnuconfig/config.guess config/config.guess || die
 		ln -s "${EPREFIX}"/usr/share/gnuconfig/config.sub config/config.sub || die
 	fi
+	# Flatcar: Replace udevdir variable with proper udev directory.
+	sed -i -e 's#^\(udevdir\s\+=\).*#\1 $(get_udevdir)#' Makefile.inc.in
 }
 
 src_configure() {