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 7d3a00196a..a403a58e57 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
@@ -49,8 +49,8 @@ ACCEPT_LICENSE="* -@EULA -@CHROMEOS"
 
 # Favor our own mirrors over Gentoo's
 GENTOO_MIRRORS="
-    http://storage.core-os.net/mirror/portage-stable/
-    http://storage.core-os.net/mirror/coreos/
+    https://storage.core-os.net/mirror/portage-stable/
+    https://storage.core-os.net/mirror/coreos/
     http://distfiles.gentoo.org/
 "