diff --git a/sdk_container/src/third_party/portage-stable/eclass/toolchain-funcs.eclass b/sdk_container/src/third_party/portage-stable/eclass/toolchain-funcs.eclass
index 77fb304940..b3956c9441 100644
--- a/sdk_container/src/third_party/portage-stable/eclass/toolchain-funcs.eclass
+++ b/sdk_container/src/third_party/portage-stable/eclass/toolchain-funcs.eclass
@@ -1,10 +1,12 @@
 # Copyright 2002-2021 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
+# Flatcar: Support EAPI 4.
+
 # @ECLASS: toolchain-funcs.eclass
 # @MAINTAINER:
 # Toolchain Ninjas <toolchain@gentoo.org>
-# @SUPPORTED_EAPIS: 5 6 7 8
+# @SUPPORTED_EAPIS: 4 5 6 7 8
 # @BLURB: functions to query common info about the toolchain
 # @DESCRIPTION:
 # The toolchain-funcs aims to provide a complete suite of functions
@@ -15,7 +17,7 @@
 
 case ${EAPI:-0} in
 	# EAPI=0 is still used by crossdev, bug #797367
-	0|5|6|7|8) ;;
+	0|4|5|6|7|8) ;;
 	*) die "${ECLASS}: EAPI ${EAPI:-0} not supported" ;;
 esac