diff --git a/helmfile/apps/open-xchange/values-oxconnector.yaml.gotmpl b/helmfile/apps/open-xchange/values-oxconnector.yaml.gotmpl
index 98d8e0e7..9f88b461 100644
--- a/helmfile/apps/open-xchange/values-oxconnector.yaml.gotmpl
+++ b/helmfile/apps/open-xchange/values-oxconnector.yaml.gotmpl
@@ -45,7 +45,7 @@ oxConnector:
   oxDefaultContext: "1"
   oxImapServer: "imap://127.0.0.1:143"
   oxLocalTimezone: "Europe/Berlin"
-  oxLanguage: "de_DE"
+  oxLanguage: {{ .Values.functional.internationalization.defaultLanguage | quote }}
   oxMasterAdmin: "admin"
   oxMasterPassword: {{ .Values.secrets.oxAppSuite.adminPassword | quote }}
   oxSmtpServer: "smtp://127.0.0.1:587"
diff --git a/helmfile/apps/xwiki/values.yaml.gotmpl b/helmfile/apps/xwiki/values.yaml.gotmpl
index 1019010e..c3448ed3 100644
--- a/helmfile/apps/xwiki/values.yaml.gotmpl
+++ b/helmfile/apps/xwiki/values.yaml.gotmpl
@@ -184,9 +184,9 @@ properties:
   "property:xwiki:LDAPUserImport.WebHome^LDAPUserImport.LDAPUserImportConfigClass.addOIDCObject": 1
   "property:xwiki:LDAPUserImport.WebHome^LDAPUserImport.LDAPUserImportConfigClass.OIDCIssuer": "https://{{ .Values.global.hosts.keycloak }}.{{ .Values.global.domain }}/realms/{{ .Values.platform.realm }}"
   "property:xwiki:XWiki.XWikiPreferences^XWiki.XWikiPreferences.colorTheme": "FlamingoThemes.Iceberg"
-  "property:xwiki:XWiki.XWikiPreferences^XWiki.XWikiPreferences.default_language": "de_DE"
+  "property:xwiki:XWiki.XWikiPreferences^XWiki.XWikiPreferences.default_language": {{ .Values.functional.internationalization.defaultLanguage | quote }}
   "property:xwiki:XWiki.XWikiPreferences^XWiki.XWikiPreferences.timezone": "Europe/Berlin"
-  "property:xwiki:XWiki.XWikiPreferences^XWiki.XWikiPreferences.languages": "de_DE"
+  "property:xwiki:XWiki.XWikiPreferences^XWiki.XWikiPreferences.languages": {{ .Values.functional.internationalization.defaultLanguage | quote }}
   "property:xwiki:FlamingoThemes.Iceberg^FlamingoThemesCode.ThemeClass.link-color": "@brand-primary"
   "property:xwiki:FlamingoThemes.Iceberg^FlamingoThemesCode.ThemeClass.btn-primary-bg": "@brand-primary"
   "property:xwiki:FlamingoThemes.Iceberg^FlamingoThemesCode.ThemeClass.navbar-default-color": "@brand-primary"
diff --git a/helmfile/environments/default/functional.yaml.gotmpl b/helmfile/environments/default/functional.yaml.gotmpl
index becd06ce..7a631a95 100644
--- a/helmfile/environments/default/functional.yaml.gotmpl
+++ b/helmfile/environments/default/functional.yaml.gotmpl
@@ -105,6 +105,16 @@ functional:
         # If the LDAP entryUUID should be used for the localpart of user's Matrix IDs following setting must be `true`.
         useImmutableIdentifierForLocalpart: false
 
+  dataProtection:
+    matrixPresence:
+      # Enable to allow information about the user presence status to be shared.
+      # Ref.: https://element-hq.github.io/synapse/latest/usage/configuration/config_documentation.html#presence
+      enabled: false
+    jitsiRoomHistory:
+      # Disable to avoid the room history to be stored in the user's browser local storage.
+      # Ref.: https://github.com/jitsi/docker-jitsi-meet/issues/898
+      enabled: true
+
   externalServices:
     nubus:
       udmRestApi:
@@ -117,16 +127,6 @@ functional:
         # List of matrix homeserver domains you want to allow federation with
         domainAllowList: []
 
-  dataProtection:
-    matrixPresence:
-      # Enable to allow information about the user presence status to be shared.
-      # Ref.: https://element-hq.github.io/synapse/latest/usage/configuration/config_documentation.html#presence
-      enabled: false
-    jitsiRoomHistory:
-      # Disable to avoid the room history to be stored in the user's browser local storage.
-      # Ref.: https://github.com/jitsi/docker-jitsi-meet/issues/898
-      enabled: true
-
   filestore:
     # Settings related to directory and filenames
     naming:
@@ -251,6 +251,18 @@ functional:
       # Ref.: https://documentation.open-xchange.com/8/ui/configuration/settings-list-of.html#mail-misc
       editRealName: false
 
+  internationalization:
+    # Most openDesk applications render their user interface in the language the user's browser is set to. But there
+    # are exceptions that can be controlled by the following setting.
+    # Beside the `de_DE` default `en_GB` has been tested.
+    # - OX App Suite: Users can set their preferred language in the App Suite's UI by navigating to
+    #   "All settings" > "General" > "Language & Time zone" > "Language", though the default language for the first
+    #   login will be set globally based on the setting below.
+    # - XWiki: The UI language of XWiki is set automatically by the language the wiki content is provided in. As XWiki
+    #   does not autodetect that content language, it has to be predefined by the setting below.
+    #   Note: For multi-language XWiki setups a customization is required for now.
+    defaultLanguage: "de_DE"
+
   migration:
     oxAppSuite:
       # Note: Only available in openDesk Enterprise.
diff --git a/helmfile/environments/default/images.yaml.gotmpl b/helmfile/environments/default/images.yaml.gotmpl
index 5523d6c3..e49a6c2c 100644
--- a/helmfile/environments/default/images.yaml.gotmpl
+++ b/helmfile/environments/default/images.yaml.gotmpl
@@ -560,7 +560,7 @@ images:
     # upstreamRepository: "bmi/opendesk/components/platform-development/images/opendesk-nubus"
     registry: "registry.opencode.de"
     repository: "bmi/opendesk/components/platform-development/images/opendesk-nubus"
-    tag: "1.15.0@sha256:5ffb3106bf896a215fd7ae5d6646f19b50f0e46c11561d763938479d95aaa807"
+    tag: "1.15.1@sha256:e9c46d93abe6d7a8abcd2dc5cd38f178cd3b78f971f81b34fa5bd27270604db8"
   nubusOpendeskExtensionA2gMapper:
     # providerCategory: "Platform"
     # providerResponsible: "openDesk"