Index: wp-content/themes/twentytwelve/functions.php
===================================================================
--- wp-content/themes/twentytwelve/functions.php	(revision 21358)
+++ wp-content/themes/twentytwelve/functions.php	(working copy)
@@ -113,7 +113,7 @@
  	 */
 	$options = $twentytwelve_options->get_theme_options();
 	if ( $options['enable_fonts'] )
-		wp_enqueue_style( 'twentytwelve-fonts', 'http://fonts.googleapis.com/css?family=Open+Sans:400italic,700italic,400,700' );
+		wp_enqueue_style( 'twentytwelve-fonts', '//fonts.googleapis.com/css?family=Open+Sans:400italic,700italic,400,700' );
 
 	/**
 	 * Load our main CSS file.