diff --git a/_includes/themes/twitter/my.html b/_includes/themes/twitter/my.html
index f958cd26..60ee4659 100644
--- a/_includes/themes/twitter/my.html
+++ b/_includes/themes/twitter/my.html
@@ -4,6 +4,7 @@
   <head>
     <meta charset='utf-8' />
     <meta http-equiv="X-UA-Compatible" content="chrome=1" />
+    <meta name="viewport" content="width=device-width, initial-scale=1">
     <meta name="description" content="Spectrum 2 : Spectrum 2 IM transports" />
 
     <link href="/css/style.css" rel="stylesheet" type="text/css" media="all">
diff --git a/_includes/themes/twitter/myconfig.html b/_includes/themes/twitter/myconfig.html
index 7a66d01d..71aaaa62 100644
--- a/_includes/themes/twitter/myconfig.html
+++ b/_includes/themes/twitter/myconfig.html
@@ -4,6 +4,7 @@
   <head>
     <meta charset='utf-8' />
     <meta http-equiv="X-UA-Compatible" content="chrome=1" />
+    <meta name="viewport" content="width=device-width, initial-scale=1">
     <meta name="description" content="Spectrum 2 : Spectrum 2 IM transports" />
 
     <link href="/css/style_config.css" rel="stylesheet" type="text/css" media="all">
