diff --git a/sdk_container/src/third_party/coreos-overlay/sys-kernel/coreos-sources/coreos-sources-4.16.7.ebuild b/sdk_container/src/third_party/coreos-overlay/sys-kernel/coreos-sources/coreos-sources-4.16.7.ebuild
index de3eb756b6..228579ce07 100644
--- a/sdk_container/src/third_party/coreos-overlay/sys-kernel/coreos-sources/coreos-sources-4.16.7.ebuild
+++ b/sdk_container/src/third_party/coreos-overlay/sys-kernel/coreos-sources/coreos-sources-4.16.7.ebuild
@@ -25,6 +25,10 @@ fi
 
 KEYWORDS="amd64 arm64"
 IUSE=""
+RDEPEND+="
+	sys-devel/bison
+	sys-devel/flex
+"
 
 # XXX: Note we must prefix the patch filenames with "z" to ensure they are
 # applied _after_ a potential patch-${KV}.patch file, present when building a