diff --git a/src/pages/index.js b/src/pages/index.js
index 2bd5a77..3657232 100644
--- a/src/pages/index.js
+++ b/src/pages/index.js
@@ -14,7 +14,7 @@ class BlogIndex extends React.Component {
 
     return (
       <Layout location={this.props.location}>
-        <Helmet title={siteTitle} />
+        <Helmet title={siteTitle} htmlAttributes={{ lang: 'en' }} />
         <Bio />
         {posts.map(({ node }) => {
           const title = get(node, 'frontmatter.title') || node.fields.slug
diff --git a/src/templates/blog-post.js b/src/templates/blog-post.js
index 8dfb68c..9e54c49 100644
--- a/src/templates/blog-post.js
+++ b/src/templates/blog-post.js
@@ -15,7 +15,10 @@ class BlogPostTemplate extends React.Component {
 
     return (
       <Layout location={this.props.location}>
-        <Helmet title={`${post.frontmatter.title} | ${siteTitle}`} />
+        <Helmet
+          title={`${post.frontmatter.title} | ${siteTitle}`}
+          htmlAttributes={{ lang: 'en' }}
+        />
         <h1>{post.frontmatter.title}</h1>
         <p
           style={{