diff --git a/chart/templates/postgres-cluster.yaml b/chart/templates/postgres-cluster.yaml
index d31bfe4..66c6ae9 100644
--- a/chart/templates/postgres-cluster.yaml
+++ b/chart/templates/postgres-cluster.yaml
@@ -35,6 +35,17 @@ spec:
     initdb:
       database: {{ .Values.postgres.database }}
       owner: {{ .Values.postgres.owner }}
+      {{- with .Values.postgres.locale }}
+      # initdb-only: collation and ctype are fixed when the database is created.
+      # Changing them on a running cluster means a new cluster and a restore.
+      encoding: {{ .encoding | default "UTF8" }}
+      {{- with .collate }}
+      localeCollate: {{ . }}
+      {{- end }}
+      {{- with .ctype }}
+      localeCType: {{ . }}
+      {{- end }}
+      {{- end }}
   {{- if .Values.postgres.allowCreateDatabase }}
   # Development only. pytest-django creates and drops its own test database on
   # every run, which the bootstrap owner role cannot do by default. CNPG
diff --git a/chart/values.yaml b/chart/values.yaml
index 3337da0..10c12b4 100644
--- a/chart/values.yaml
+++ b/chart/values.yaml
@@ -145,6 +145,12 @@ postgres:
   image: ghcr.io/cloudnative-pg/postgresql:17
   database: typelearn
   owner: typelearn
+  # Collation/ctype for the initial database, e.g. en_US.UTF-8. Empty keeps
+  # CNPG's default (C). Only read at bootstrap; it cannot be changed in place.
+  locale: {}
+  #  encoding: UTF8
+  #  collate: en_US.UTF-8
+  #  ctype: en_US.UTF-8
   storage:
     size: 1Gi
     # Empty uses the cluster's default StorageClass.