diff --git a/docs/page.xsl b/docs/page.xsl
index a51587db6c..7dcbc2d7a4 100644
--- a/docs/page.xsl
+++ b/docs/page.xsl
@@ -21,7 +21,7 @@
     <xsl:param name="asset_href_base"/>
     <xsl:text disable-output-escaping="yes">&lt;!DOCTYPE html&gt;
 </xsl:text>
-    <html data-sourcedoc="{$pagesrc}">
+    <html lang="en" data-sourcedoc="{$pagesrc}">
       <xsl:comment>
         This file is autogenerated from <xsl:value-of select="$pagesrc"/>
         Do not edit this file. Changes will be lost.
