diff --git a/source/themes/opdavies/opdavies/_layouts/default.html.twig b/source/themes/opdavies/opdavies/_layouts/default.html.twig
index cadd5fe19..7d53f2c12 100644
--- a/source/themes/opdavies/opdavies/_layouts/default.html.twig
+++ b/source/themes/opdavies/opdavies/_layouts/default.html.twig
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html lang="en" class="no-js">
+<html lang="en-GB" class="no-js">
   <head>
     <meta charset="utf-8">
     <meta http-equiv="X-UA-Compatible" content="IE=edge">
