diff --git a/wp-includes/post.php b/wp-includes/post.php
index a972512d94..57f0795e9c 100644
--- a/wp-includes/post.php
+++ b/wp-includes/post.php
@@ -942,7 +942,7 @@ function register_post_type($post_type, $args = array()) {
 			$wp_rewrite->add_rule( "{$archive_slug}/page/([0-9]{1,})/?$", "index.php?post_type=$post_type" . '&paged=$matches[1]', 'top' );
 		}
 
-		$wp_rewrite->add_permastruct($post_type, "{$archive_slug}/%$post_type%", $args->rewrite['with_front'], $args->permalink_epmask);
+		$wp_rewrite->add_permastruct($post_type, "{$args->rewrite['slug']}/%$post_type%", $args->rewrite['with_front'], $args->permalink_epmask);
 	}
 
 	if ( $args->register_meta_box_cb )