diff --git a/.env.sample b/.env.sample
index e99fc96..2b4d548 100644
--- a/.env.sample
+++ b/.env.sample
@@ -11,6 +11,10 @@ MEDIAWIKI_EMAIL_CONTACT="info@wiki.example.com"
 MEDIAWIKI_EMAIL_FROM="wiki@wiki.example.com"
 MEDIAWIKI_LOGO_FILE='$wgResourceBasePath/resources/assets/wiki.png'
 
+# list of language options (without ".json"):
+# https://gerrit.wikimedia.org/g/mediawiki/core/%2B/HEAD/languages/i18n
+MEDIAWIKI_LANGUAGE="en"
+
 MEDIAWIKI_IS_PRIVATE=1
 
 MEDIAWIKI_DEBUG=0
diff --git a/LocalSettings.php.tmpl b/LocalSettings.php.tmpl
index 41a2833..62e500e 100644
--- a/LocalSettings.php.tmpl
+++ b/LocalSettings.php.tmpl
@@ -84,7 +84,7 @@ $wgShellLocale = "C.UTF-8";
 #$wgCacheDirectory = "$IP/cache";
 
 # Site language code, should be one of the list in ./languages/data/Names.php
-$wgLanguageCode = "en";
+$wgLanguageCode = "{{ env "MEDIAWIKI_LANGUAGE" }}";
 
 $wgSecretKey = rtrim(file_get_contents('/run/secrets/mediawiki_secret_key'));
 
diff --git a/abra.sh b/abra.sh
index 52c49d9..baa89a5 100644
--- a/abra.sh
+++ b/abra.sh
@@ -1,4 +1,4 @@
-export LOCAL_SETTINGS_CONF_VERSION=v20
+export LOCAL_SETTINGS_CONF_VERSION=v21
 export HTACCESS_CONF_VERSION=v1
 export ENTRYPOINT_CONF_VERSION=v19
 export COMPOSER_LOCAL_CONF_VERSION=v5
diff --git a/compose.yml b/compose.yml
index 87631bb..29e0971 100644
--- a/compose.yml
+++ b/compose.yml
@@ -14,6 +14,7 @@ services:
       - MEDIAWIKI_LOGO_FILE
       - MEDIAWIKI_IS_PRIVATE
       - MEDIAWIKI_DEBUG
+      - MEDIAWIKI_LANGUAGE=${MEDIAWIKI_LANGUAGE:-en}
       - SAML_ENABLED
       - OPENID_ENABLED
       - DB_HOST=db