diff --git a/.gitea/actions/deploy-obs/action.yml b/.gitea/actions/deploy-obs/action.yml
index 59a90f37..f8825933 100644
--- a/.gitea/actions/deploy-obs/action.yml
+++ b/.gitea/actions/deploy-obs/action.yml
@@ -82,8 +82,9 @@ runs:
       # required keys before containers start. Catches undefined variables and
       # YAML errors in config files updated by the previous step.
       # --env-file order: obs.env first (git-tracked defaults), obs-secrets.env
-      # second (CI-written secrets). Later files win on duplicate keys, so
-      # obs-secrets.env overrides POSTGRES_HOST set in obs.env.
+      # second (CI-written secrets). Later files win on duplicate keys. POSTGRES_HOST
+      # is environment-specific and supplied only by obs-secrets.env — obs.env
+      # documents it but deliberately does not set a value.
       run: |
         docker compose \
           -f /opt/familienarchiv/docker-compose.observability.yml \