diff --git a/README.md b/README.md
index 2312e4a..d8a079f 100644
--- a/README.md
+++ b/README.md
@@ -73,7 +73,7 @@ Quickstart a new site with the Zen theme by using the [Zen demo repo as a templa
 
 ## Minimum Hugo version
 
-Hugo version 0.146.0 or higher is required. Since v6 the extended version is no longer needed as it was with v5 and earlier.
+Hugo version 0.158.0 or higher is required. Since v6 the extended version is no longer needed as it was with v5 and earlier.
 
 
 ## Installation
@@ -152,6 +152,7 @@ hugo server --themesDir ../..
 
 ## Version 6.x 2026-03-10
 
+* Minimum Hugo version is now v0.158.0 (since 6.3).
 * Converted from sass to modern vanilla css with nesting and layers. Please check [CSS Nesting | Can I use](https://caniuse.com/css-nesting) to see if you are comfortable with css nesting support in browsers before updating to v6.
 * No changes to styles or templates so sites should look identical, if the browser support nesting.
 
diff --git a/hugo.yaml b/hugo.yaml
index 007a857..61c9b36 100644
--- a/hugo.yaml
+++ b/hugo.yaml
@@ -1,4 +1,4 @@
 module:
   hugoVersion:
     extended: false
-    min: "0.146.0"
+    min: "0.158.0"
diff --git a/layouts/_partials/head/meta.html b/layouts/_partials/head/meta.html
index 728fc06..8cfcd31 100644
--- a/layouts/_partials/head/meta.html
+++ b/layouts/_partials/head/meta.html
@@ -22,6 +22,6 @@
 <link rel="canonical" href="{{ .Permalink }}">
 {{ if .IsTranslated -}}
 {{ range .Translations -}}
-<link rel="alternate" hreflang="{{ .Site.Language.LanguageCode | default .Lang }}" href="{{ .Permalink }}">
+<link rel="alternate" hreflang="{{ .Site.Language.Locale | default .Language.Name }}" href="{{ .Permalink }}">
 {{ end -}}
 {{ end -}}
diff --git a/layouts/_partials/language-selector.html b/layouts/_partials/language-selector.html
index f91e872..6378537 100644
--- a/layouts/_partials/language-selector.html
+++ b/layouts/_partials/language-selector.html
@@ -6,12 +6,12 @@
 <ul class="flex-inline mx--0">
 {{ if .IsTranslated -}}
 {{ range .Translations -}}
-<li><a rel="alternate" href="{{ .RelPermalink }}" hreflang="{{ .Site.Language.LanguageCode | default .Lang }}" lang="{{ .Site.Language.LanguageCode | default .Lang }}">{{ .Language.LanguageName }}</a></li>
+<li><a rel="alternate" href="{{ .RelPermalink }}" hreflang="{{ .Site.Language.Locale | default .Language.Name }}" lang="{{ .Site.Language.Locale | default .Language.Name }}">{{ .Language.Label }}</a></li>
 {{ end -}}
 {{ else -}}
-{{ range site.Languages -}}
-{{ if ne site.Language.Lang .Lang -}}
-<li><a rel="alternate" href="{{ .Lang | relURL }}" hreflang="{{ .Lang }}" lang="{{ .Lang }}">{{ .LanguageName }}</a></li>
+{{ range hugo.Sites -}}
+{{ if ne $.Language.Name .Language.Name -}}
+<li><a rel="alternate" href="{{ .Home.RelPermalink }}" hreflang="{{ .Language.Locale | default .Language.Name }}" lang="{{ .Language.Locale | default .Language.Name }}">{{ .Language.Label }}</a></li>
 {{ end -}}
 {{ end -}}
 {{ end -}}
diff --git a/layouts/baseof.html b/layouts/baseof.html
index 708fac1..fa1ec5d 100644
--- a/layouts/baseof.html
+++ b/layouts/baseof.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html class="nojs" lang="{{ site.Language.LanguageCode | default site.Language.Lang }}" dir="{{ site.Language.LanguageDirection | default "ltr" }}">
+<html class="nojs" lang="{{ site.Language.Locale | default site.Language.Name }}" dir="{{ site.Language.Direction | default "ltr" }}">
 <head>
 <meta charset="utf-8">
 <meta name="viewport" content="width=device-width">
diff --git a/layouts/list.json.json b/layouts/list.json.json
index 1eb70e0..6923bc4 100644
--- a/layouts/list.json.json
+++ b/layouts/list.json.json
@@ -19,7 +19,7 @@
     {{ with .OutputFormats.Get "JSON" -}}
     "feed_url": "{{ .Permalink }}",
     {{ end -}}
-    {{ with site.Language.LanguageCode -}}
+    {{ with site.Language.Locale -}}
     "language": "{{ . }}",
     {{ end -}}
     {{ with $.Param "icon" -}}
diff --git a/layouts/micro/rss.xml b/layouts/micro/rss.xml
index 02e3c3c..b54b992 100644
--- a/layouts/micro/rss.xml
+++ b/layouts/micro/rss.xml
@@ -4,7 +4,7 @@
     <link>{{ .Permalink }}</link>
     <description>Micro blog {{ i18n "string_by" }} {{ with site.Params.author.name }}{{ . }}{{ end }}, {{ i18n "string_follow" }} @{{ with $.Param "microusername" }}{{ . }}{{ end }} {{ i18n "string_at" }} https://micro.blog/{{ with $.Param "microusername" }}{{ . }}{{ end }}</description>
     <generator>Hugo -- gohugo.io</generator>
-    {{ with site.Language.LanguageCode -}}
+    {{ with site.Language.Locale -}}
     <language>{{ . }}</language>
     {{ end -}}
     {{ with site.Params.author.email -}}
diff --git a/layouts/podcast/rss.xml b/layouts/podcast/rss.xml
index c6a0560..84eeadc 100644
--- a/layouts/podcast/rss.xml
+++ b/layouts/podcast/rss.xml
@@ -5,7 +5,7 @@
     <link>{{ .Permalink }}</link>
     <description>{{ site.Params.Podcast.Description | default site.Params.Description }}</description>
     <generator>Hugo -- gohugo.io</generator>
-    <language>{{ site.Params.Podcast.Lang | default site.Language.LanguageCode }}</language>
+    <language>{{ site.Params.Podcast.Lang | default site.Language.Locale }}</language>
     {{ with site.Params.author.email -}}
     <managingEditor>{{ . }}{{ with site.Params.author.name }} ({{ . }}){{ end }}</managingEditor>
     {{ end -}}
diff --git a/layouts/rss.xml b/layouts/rss.xml
index d009885..c276e68 100644
--- a/layouts/rss.xml
+++ b/layouts/rss.xml
@@ -17,7 +17,7 @@
     <link>{{ .Permalink }}</link>
     <description>{{ i18n "string_recent_content" }} {{ if ne .Title site.Title }}{{ with .Title }}{{ i18n "string_in" }} {{ . }} {{ end }}{{ end }}{{ i18n "string_on" }} {{ site.Title }}</description>
     <generator>Hugo</generator>
-    {{- with site.Language.LanguageCode }}
+    {{- with site.Language.Locale }}
     <language>{{ . }}</language>
     {{- end }}
     {{- with site.Params.author.email }}
diff --git a/theme.toml b/theme.toml
index fac42eb..7c9fe04 100644
--- a/theme.toml
+++ b/theme.toml
@@ -6,7 +6,7 @@ license = "GPLv2"
 licenselink = "http://www.gnu.org/licenses/old-licenses/gpl-2.0.html"
 tags = ["accessible", "multilingual", "responsive", "blog", "search", "math", "podcast"]
 features = ["accessible", "multilingual", "responsive", "grid", "search", "matomo", "jsonfeed", "math", "podcast"]
-min_version = "0.146.0"
+min_version = "0.158.0"
 
 [author]
   name = "Fredrik Jonsson"