diff --git a/templates/calcom/.felhom.yml b/templates/calcom/.felhom.yml
index 2230bcd..dca3e68 100644
--- a/templates/calcom/.felhom.yml
+++ b/templates/calcom/.felhom.yml
@@ -10,7 +10,7 @@ subdomain: "cal"
 slug: "calcom"
 # catalog_since: the date THIS repo last changed this app's pinned images. Any commit that
 # changes an image: line must set this to the same day (see CLAUDE.md).
-catalog_since: "2026-07-18"
+catalog_since: "2026-09-28"
 
 # --- Resource hints (displayed on deploy screen) ---
 resources:
@@ -136,3 +136,9 @@ i18n:
         label: 'Encryption key'
       - env_var: NEXTAUTH_SECRET
         label: 'NextAuth encryption key'
+
+# update_ladder — the test record: one tested step per line, oldest first (JSON flow mappings,
+# `09-update-architecture.md` §6.4 part 4). WRITTEN BY scripts/upgrade-test.py, never by hand;
+# gated by scripts/check-test-record.py. An image: move without a proven entry here is refused.
+update_ladder:
+  - {"from": {"calcom": "calcom/cal.com:v6.2.0", "calcom-postgres": "postgres:16-alpine"}, "to": {"calcom": "calcom/cal.com:v6.2.0", "calcom-postgres": "postgres:18-alpine"}, "digest": {"calcom": "sha256:ace3bb1219fb7306585ab9f4d94d41af7ee064c343db0498173436bbe857bd49", "calcom-postgres": "sha256:77f585114c32fbca283dc835b0596f4e52b51b4c6662d7810b2f4084f60a1873"}, "verdict": "proven", "tested_at": "2026-09-28T09:44:27Z", "harness_version": 4, "evidence": "felhom.eu/documentation/audits/pg-calcom-claper-2026-09-28/bench/apps/calcom/bench/evidence/MV-calcom/verdict.json", "box_evidence": "felhom.eu/documentation/audits/pg-calcom-claper-2026-09-28/box/calcom/box-verdict-calcom.json", "memory_peak_pct": 61.5, "marks": {"files_may_change": false, "needs_person": null, "memory_tight": false}, "memory_basis": "anon", "memory_cgroup_peak_pct": 100.0, "engine_conversion": {"service": "calcom-postgres", "engine": "postgres", "from": 16, "to": 18}}
diff --git a/templates/calcom/docker-compose.yml b/templates/calcom/docker-compose.yml
index 2ec365b..800fa2d 100644
--- a/templates/calcom/docker-compose.yml
+++ b/templates/calcom/docker-compose.yml
@@ -56,7 +56,7 @@ services:
       - "traefik.http.services.calcom.loadbalancer.server.port=3000"
 
   calcom-postgres:
-    image: postgres:16-alpine
+    image: postgres:18-alpine
     container_name: calcom-postgres
     restart: unless-stopped
     environment:
@@ -65,7 +65,7 @@ services:
       - POSTGRES_DB=calcom
       - TZ=Europe/Budapest
     volumes:
-      - calcom_postgres_data:/var/lib/postgresql/data
+      - calcom_postgres_data:/var/lib/postgresql
     networks:
       - calcom-internal
     deploy: