diff --git a/global/overlay/etc/puppet/cosmos-rules.yaml b/global/overlay/etc/puppet/cosmos-rules.yaml
index 16b396b..b09f60a 100644
--- a/global/overlay/etc/puppet/cosmos-rules.yaml
+++ b/global/overlay/etc/puppet/cosmos-rules.yaml
@@ -1,3 +1,4 @@
+---
 # Note that the matching is done with re.match()
 '.*\.cert\.sunet\.se$':
   soc: