diff --git a/sdk_container/src/third_party/coreos-overlay/metadata/layout.conf b/sdk_container/src/third_party/coreos-overlay/metadata/layout.conf
index 3320dad4b6..a83f5b1222 100644
--- a/sdk_container/src/third_party/coreos-overlay/metadata/layout.conf
+++ b/sdk_container/src/third_party/coreos-overlay/metadata/layout.conf
@@ -1,5 +1,5 @@
 masters = portage-stable
 thin-manifests = true
-use-manifests = true
+use-manifests = strict
 cache-format = md5-dict
 profile-formats = portage-2