diff --git a/_layouts/default.html b/_layouts/default.html
index ea1a103..98c4a1f 100644
--- a/_layouts/default.html
+++ b/_layouts/default.html
@@ -5,7 +5,7 @@
         <meta http-equiv="X-UA-Compatible" content="IE=edge">
         <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1">
         <title property="og:title">{% if page.lang_title %}{{ page.lang_title }} · {% endif %}{{ site.name }}</title>
-        <link href="http://fonts.googleapis.com/css?family=PT+Sans|Roboto+Slab|Droid+Sans+Mono" rel="stylesheet" type="text/css">
+        <link href="//fonts.googleapis.com/css?family=PT+Sans|Roboto+Slab|Droid+Sans+Mono" rel="stylesheet" type="text/css">
         <link rel="stylesheet" href="{{ site.url }}/static/style.css">
 
         <link rel="icon" type="image/png" href="{{ site.url }}/static/favicon-32x32.png" sizes="32x32" />
@@ -27,7 +27,7 @@
         <meta content="@treffynnon" name="twitter:creator">
         <meta content="{{ site.domain }}" name="twitter:domain">
 
-        <link href="http://plus.google.com/+SimonHolywell" rel="author">
+        <link href"//plus.google.com/+SimonHolywell" rel="author">
 
         <link rel="canonical" href="{{ site.url }}{{ page.url | replace:'index.html',''}}">
         <link rel="alternate" hreflang="x-default" href="{{ site.url }}/">
@@ -37,7 +37,7 @@
         <meta itemprop="wordCount" content="{{ content | number_of_words }}">
         <meta itemprop="about" content="{{ site.description }}">
         <meta itemprop="audience" content="SQL programmers">
-        <meta itemprop="license" content="http://creativecommons.org/licenses/by-sa/4.0/">
+        <meta itemprop="license" content="https://creativecommons.org/licenses/by-sa/4.0/">
         <meta itemprop="version" content="1.0.1">
         <meta itemprop="proficiencyLevel" content="Beginner">
         <meta itemprop="dependencies" content="SQL knowledge">