diff --git a/sdk_container/src/third_party/coreos-overlay/profiles/coreos/base/package.accept_keywords b/sdk_container/src/third_party/coreos-overlay/profiles/coreos/base/package.accept_keywords
index 5c4464aa56..60f5b71286 100644
--- a/sdk_container/src/third_party/coreos-overlay/profiles/coreos/base/package.accept_keywords
+++ b/sdk_container/src/third_party/coreos-overlay/profiles/coreos/base/package.accept_keywords
@@ -4,6 +4,9 @@
 #
 # Keywords for all packages used by Flatcar.
 
+# Keep versions on both arches in sync.
+=app-arch/pigz-2.8 ~amd64
+
 # Seems to be the only available ebuild in portage-stable right now.
 =app-crypt/adcli-0.9.2 ~amd64 ~arm64