Index: wp-admin/admin-header.php
===================================================================
--- wp-admin/admin-header.php	(revision 24296)
+++ wp-admin/admin-header.php	(working copy)
@@ -87,13 +87,13 @@
 
 if ( isset( $post ) && is_a( $post, 'WP_Post' ) && post_type_supports( get_post_type(), 'post-formats' ) ) {
 	$post_format = get_post_format();
-	if ( ! $post_format ) {
+
+	if ( ! empty( $_REQUEST['format'] ) && in_array( $_REQUEST['format'], get_post_format_slugs() ) )
+		$post_format = $_REQUEST['format'];
+
+	if ( ! $post_format )
 		$post_format = 'standard';
 
-		if ( ! empty( $_REQUEST['format'] ) && in_array( $_REQUEST['format'], get_post_format_slugs() ) )
-			$post_format = $_REQUEST['format'];
-	}
-
 	$admin_body_class .= ' wp-format-' . $post_format;
 
 	$show_post_format_ui = false;
Index: wp-admin/edit-form-advanced.php
===================================================================
--- wp-admin/edit-form-advanced.php	(revision 24296)
+++ wp-admin/edit-form-advanced.php	(working copy)
@@ -136,13 +136,12 @@
 	wp_enqueue_style( 'wp-mediaelement' );
 	$post_format = get_post_format();
 
-	if ( ! $post_format ) {
+	if ( ! empty( $_REQUEST['format'] ) && in_array( $_REQUEST['format'], get_post_format_slugs() ) )
+		$post_format = $_REQUEST['format'];
+
+	if ( ! $post_format )
 		$post_format = 'standard';
 
-		if ( ! empty( $_REQUEST['format'] ) && in_array( $_REQUEST['format'], get_post_format_slugs() ) )
-			$post_format = $_REQUEST['format'];
-	}
-
 	$format_class = " class='wp-format-{$post_format}'";
 
 	$all_post_formats = array(
@@ -185,7 +184,9 @@
 			$active_post_type_slug = $slug;
 		}
 
-		$post_format_options .= '<a ' . $class . ' href="?format=' . $slug . '" data-description="' . $attr['description'] . '" data-wp-format="' . $slug . '" title="' . ucfirst( $slug ) . '"><div class="' . $slug . '"></div><span class="post-format-title">' . ucfirst( $slug ) . '</span></a>';
+		$url = add_query_arg( 'format', $slug );
+
+		$post_format_options .= '<a ' . $class . ' href="' . esc_url( $url ) . '" data-description="' . $attr['description'] . '" data-wp-format="' . $slug . '" title="' . ucfirst( $slug ) . '"><div class="' . $slug . '"></div><span class="post-format-title">' . ucfirst( $slug ) . '</span></a>';
 	}
 
 	$current_post_format = array( 'currentPostFormat' => esc_html( $active_post_type_slug ) );