diff --git a/changes/changelog.d/1130.enhancement b/changes/changelog.d/1130.enhancement
new file mode 100644
index 000000000..07318ba95
--- /dev/null
+++ b/changes/changelog.d/1130.enhancement
@@ -0,0 +1 @@
+Set proper lang attribute on HTML document (#1130)
\ No newline at end of file
diff --git a/front/src/App.vue b/front/src/App.vue
index de76d1c2a..702fd36b9 100644
--- a/front/src/App.vue
+++ b/front/src/App.vue
@@ -369,6 +369,8 @@ export default {
       immediate: true,
       handler(newValue) {
         let self = this
+        let htmlLocale = newValue.toLowerCase().replace('_', '-')
+        document.documentElement.setAttribute('lang', htmlLocale);
         if (newValue === 'en_US') {
           self.$language.current = 'noop'
           self.$language.current = newValue