diff --git a/roles/common/defaults/main.yml b/roles/common/defaults/main.yml
index df3c20e26d035424d2a459ffeb2b37c4bb929b8e..65a7ef0de0758a98541dc78b86dfd98d0cb8a088 100644
--- a/roles/common/defaults/main.yml
+++ b/roles/common/defaults/main.yml
@@ -4,6 +4,6 @@ enable_backup: False
 common_packages: []
 os_users: []
 os_groups: []
-ca_certificates: []
+ca_certificates: {}
 incoming_connection_limit: 3/second
 incoming_connection_limit_burst: 9
\ No newline at end of file