Index: link-template.php
===================================================================
--- link-template.php	(revision 38088)
+++ link-template.php	(working copy)
@@ -3992,7 +3992,7 @@
 		'r' => $args['rating'],
 	);
 
-	if ( is_ssl() ) {
+	if ( is_ssl() || $args['scheme'] === 'https' ) {
 		$url = 'https://secure.gravatar.com/avatar/' . $email_hash;
 	} else {
 		$url = sprintf( 'http://%d.gravatar.com/avatar/%s', $gravatar_server, $email_hash );
@@ -4000,7 +4000,7 @@
 
 	$url = add_query_arg(
 		rawurlencode_deep( array_filter( $url_args ) ),
-		set_url_scheme( $url, $args['scheme'] )
+		$url
 	);
 
 	/**