diff --git a/Art/Flipping/index.html b/Art/Flipping/index.html
index 1d3d0365d..6e1323426 100644
--- a/Art/Flipping/index.html
+++ b/Art/Flipping/index.html
@@ -4,6 +4,7 @@
     <title>Flippers</title>
     <link rel="stylesheet" type="text/css" href="style.css">
 </head>
+<html lang="en">
 <body>
     <h1>Flip the cards once they stop moving to see the hidden message.</h1>
     <div class="container">
