diff --git a/external_full.xml b/external_full.xml
index 7d874d0..e3c8e89 100644
--- a/external_full.xml
+++ b/external_full.xml
@@ -84,6 +84,8 @@
            name="third_party/overlays/portage-stable" />
   <project path="src/repohooks"
            name="cos/repohooks" />
+  <project path="src/platform/cobble"
+           name="cos/cobble" />
   <project path="manifest" name="cos/manifest" >
       <copyfile src="LICENSE" dest="LICENSE" />
   </project>