diff --git a/sdk_container/src/third_party/coreos-overlay/profiles/coreos/base/make.defaults b/sdk_container/src/third_party/coreos-overlay/profiles/coreos/base/make.defaults
index 6f15ef413a..eeded5e9ff 100644
--- a/sdk_container/src/third_party/coreos-overlay/profiles/coreos/base/make.defaults
+++ b/sdk_container/src/third_party/coreos-overlay/profiles/coreos/base/make.defaults
@@ -130,3 +130,6 @@ BINPKG_COMPRESS=bzip2
 
 # Enable cgo by default. Required for the docker device-mapper driver to compile.
 CGO_ENABLED=1
+
+# Keep using old binary format for now.
+BINPKG_FORMAT=xpak