diff --git a/resources/content_server/browse/browse.html b/resources/content_server/browse/browse.html
index 1ae0d005f4..36f7199eb9 100644
--- a/resources/content_server/browse/browse.html
+++ b/resources/content_server/browse/browse.html
@@ -7,7 +7,7 @@
     <title>..:: calibre {library} ::.. {title}</title>
     <meta http-equiv="X-UA-Compatible" content="IE=100" />
     <meta name="robots" content="noindex" />
-    <link rel="icon" type="image/x-icon" href="http://calibre-ebook.com/favicon.ico" />
+    <link rel="icon" type="image/x-icon" href="//calibre-ebook.com/favicon.ico" />
 
     <link rel="stylesheet" type="text/css" href="{prefix}/static/browse/browse.css" />
     <link type="text/css" href="{prefix}/static/jquery_ui/css/humanity-custom/jquery-ui-1.8.5.custom.css" rel="stylesheet" />
diff --git a/resources/content_server/index.html b/resources/content_server/index.html
index c5a57f764b..51cc33a798 100644
--- a/resources/content_server/index.html
+++ b/resources/content_server/index.html
@@ -9,7 +9,7 @@
         <script type="text/javascript" src="{prefix}/static/date.js" charset="utf-8"></script>
         <script type="text/javascript" src="{prefix}/static/jquery.js" charset="utf-8"></script>
         <script type="text/javascript" src="{prefix}/static/gui.js" charset="utf-8"></script>
-		<link rel="icon" href="http://calibre-ebook.com/favicon.ico" type="image/x-icon" />
+		<link rel="icon" href="//calibre-ebook.com/favicon.ico" type="image/x-icon" />
 	</head>
 	<body>
 	    <div id="banner">
diff --git a/setup/plugins_mirror.py b/setup/plugins_mirror.py
index 8a5915c766..338c2989d5 100644
--- a/setup/plugins_mirror.py
+++ b/setup/plugins_mirror.py
@@ -372,7 +372,7 @@ def fetch_plugins(old_index):
     return ans
 
 def plugin_to_index(plugin, count):
-    title = '<h3><img src="http://icons.iconarchive.com/icons/oxygen-icons.org/oxygen/32/Apps-preferences-plugin-icon.png"><a href=%s title="Plugin forum thread">%s</a></h3>' % (  # noqa
+    title = '<h3><img src="//icons.iconarchive.com/icons/oxygen-icons.org/oxygen/32/Apps-preferences-plugin-icon.png"><a href=%s title="Plugin forum thread">%s</a></h3>' % (  # noqa
         quoteattr(plugin['thread_url']), escape(plugin['name']))
     released = datetime(*tuple(map(int, re.split(r'\D', plugin['last_modified'])))[:6]).strftime('%e %b, %Y').lstrip()
     details = [
@@ -416,7 +416,7 @@ def create_index(index, raw_stats):
 <!DOCTYPE html>
 <html>
 <head><meta charset="utf-8"><title>Index of calibre plugins</title>
-<link rel="icon" type="image/x-icon" href="http://calibre-ebook.com/favicon.ico" />
+<link rel="icon" type="image/x-icon" href="//calibre-ebook.com/favicon.ico" />
 <style type="text/css">
 body { background-color: #eee; }
 a { text-decoration: none }
@@ -432,7 +432,7 @@ h1 { text-align: center }
 </style>
 </head>
 <body>
-<h1><img src="http://manual.calibre-ebook.com/_static/logo.png">Index of calibre plugins</h1>
+<h1><img src="//manual.calibre-ebook.com/_static/logo.png">Index of calibre plugins</h1>
 <div style="text-align:center"><a href="stats.html">Download counts for all plugins</a></div>
 %s
 </body>
@@ -455,7 +455,7 @@ h1 { text-align: center }
 <!DOCTYPE html>
 <html>
 <head><meta charset="utf-8"><title>Stats for calibre plugins</title>
-<link rel="icon" type="image/x-icon" href="http://calibre-ebook.com/favicon.ico" />
+<link rel="icon" type="image/x-icon" href="//calibre-ebook.com/favicon.ico" />
 <style type="text/css">
 body { background-color: #eee; }
 h1 img, h3 img { vertical-align: middle; margin-right: 0.5em; }
@@ -463,7 +463,7 @@ h1 { text-align: center }
 </style>
 </head>
 <body>
-<h1><img src="http://manual.calibre-ebook.com/_static/logo.png">Stats for calibre plugins</h1>
+<h1><img src="//manual.calibre-ebook.com/_static/logo.png">Stats for calibre plugins</h1>
 <table>
 <tr><th>Plugin</th><th>Total downloads</th></tr>
 %s
@@ -537,7 +537,7 @@ def check_for_qt5_incompatibility():
 <!DOCTYPE html>
 <html>
 <head><meta charset="utf-8"><title>Stats for porting of calibre plugins to Qt 5</title>
-<link rel="icon" type="image/x-icon" href="http://calibre-ebook.com/favicon.ico" />
+<link rel="icon" type="image/x-icon" href="//calibre-ebook.com/favicon.ico" />
 <style type="text/css">
 body { background-color: #eee; }
 h1 img, h3 img { vertical-align: middle; margin-right: 0.5em; }
@@ -545,7 +545,7 @@ h1 { text-align: center }
 </style>
 </head>
 <body>
-<h1><img src="http://manual.calibre-ebook.com/_static/logo.png">Stats for porting of calibre plugins to Qt 5</h1>
+<h1><img src="//manual.calibre-ebook.com/_static/logo.png">Stats for porting of calibre plugins to Qt 5</h1>
 <p>Number of Qt 5 compatible plugins: %s<br>Number of Qt 5 incompatible plugins: %s<br>Percentage of plugins ported: %.0f%%</p>
 <h2>Plugins that have been ported</h2>
 <ul>
diff --git a/src/calibre/library/server/mobile.py b/src/calibre/library/server/mobile.py
index 8af4d3cb91..53991fe2d0 100644
--- a/src/calibre/library/server/mobile.py
+++ b/src/calibre/library/server/mobile.py
@@ -170,7 +170,7 @@ def build_index(books, num, search, sort, order, start, total, url_base, CKEYS,
     return HTML(
         HEAD(
             TITLE(__appname__ + ' Library'),
-            LINK(rel='icon', href='http://calibre-ebook.com/favicon.ico',
+            LINK(rel='icon', href='//calibre-ebook.com/favicon.ico',
                 type='image/x-icon'),
             LINK(rel='stylesheet', type='text/css',
                 href=prefix+'/mobile/style.css'),
