diff --git a/kas/corstone1000-base.yml b/kas/corstone1000-base.yml
index 6fda343b..6594caa5 100644
--- a/kas/corstone1000-base.yml
+++ b/kas/corstone1000-base.yml
@@ -5,7 +5,7 @@ distro: poky-tiny
 
 defaults:
   repos:
-    refspec: master
+    refspec: mickledore
 
 repos:
   meta-arm: