diff --git a/src/opnsense/service/templates/OPNsense/IDS/custom.yaml.sample b/src/opnsense/service/templates/OPNsense/IDS/custom.yaml.sample
index 17d869edf..fe8f738a9 100644
--- a/src/opnsense/service/templates/OPNsense/IDS/custom.yaml.sample
+++ b/src/opnsense/service/templates/OPNsense/IDS/custom.yaml.sample
@@ -1 +1,2 @@
+%YAML 1.1
 # empty stub for custom modifications