diff --git a/_includes/js-selector.html b/_includes/js-selector.html
index b37d7103fff..65c64537d15 100644
--- a/_includes/js-selector.html
+++ b/_includes/js-selector.html
@@ -33,7 +33,7 @@
or page.layout == 'category'
or page.layout == 'tag'
%}
- {% assign locale = site.lang | split: '-' | first %}
+ {% assign locale = include.lang | split: '-' | first %}
{% assign urls = urls
| append: ','
diff --git a/_includes/lang.html b/_includes/lang.html
index 19558a074cd..34b50dfaab8 100644
--- a/_includes/lang.html
+++ b/_includes/lang.html
@@ -1,7 +1,9 @@
{% comment %}
Detect appearance language and return it through variable "lang"
{% endcomment %}
-{% if site.data.locales[site.lang] %}
+{% if site.data.locales[page.lang] %}
+ {% assign lang = page.lang %}
+{% elsif site.data.locales[site.lang] %}
{% assign lang = site.lang %}
{% else %}
{% assign lang = 'en' %}
diff --git a/_layouts/default.html b/_layouts/default.html
index 7e355fe98d9..6e865b920f5 100644
--- a/_layouts/default.html
+++ b/_layouts/default.html
@@ -13,7 +13,7 @@
{% endif %}
-
+
{% include head.html %}
@@ -76,7 +76,7 @@
- {% include js-selector.html %}
+ {% include js-selector.html lang=lang %}
{% if page.mermaid %}
{% include mermaid.html %}