diff --git a/charts/mailu/Chart.lock b/charts/mailu/Chart.lock
index 007e1085..b8e79e14 100644
--- a/charts/mailu/Chart.lock
+++ b/charts/mailu/Chart.lock
@@ -4,9 +4,9 @@ dependencies:
   version: 22.0.7
 - name: postgresql
   repository: https://charts.bitnami.com/bitnami
-  version: 16.7.27
+  version: 18.6.4
 - name: mariadb
   repository: https://charts.bitnami.com/bitnami
   version: 22.0.0
-digest: sha256:281a64cc591c02586a4ef68228f19de0968514b3946477e7fc5db32f3eca0672
-generated: "2025-11-16T20:41:17.136901+01:00"
+digest: sha256:37fd0be10a4dbabed5bfb50ba0ddbb3248a9fa040bb836adb09d4182bd9b0b2c
+generated: "2026-05-08T21:03:47.85034781Z"
diff --git a/charts/mailu/Chart.yaml b/charts/mailu/Chart.yaml
index 8202003f..6fbe4026 100644
--- a/charts/mailu/Chart.yaml
+++ b/charts/mailu/Chart.yaml
@@ -29,7 +29,7 @@ dependencies:
     repository: https://charts.bitnami.com/bitnami
   - condition: postgresql.enabled
     name: postgresql
-    version: 16.7.27
+    version: 18.6.4
     repository: https://charts.bitnami.com/bitnami
   - condition: mariadb.enabled
     name: mariadb