Index: wp-includes/class-wp.php
===================================================================
--- wp-includes/class-wp.php	(revision 18589)
+++ wp-includes/class-wp.php	(working copy)
@@ -284,7 +284,7 @@
 				$this->query_vars[$t->query_var] = str_replace( ' ', '+', $this->query_vars[$t->query_var] );
 
 		// Limit publicly queried post_types to those that are publicly_queryable
-		if ( isset( $this->query_vars['post_type']) ) {
+		if ( isset( $this->query_vars['post_type'] ) && ! isset( $this->query_vars['s'] ) ) {
 			$queryable_post_types = get_post_types( array('publicly_queryable' => true) );
 			if ( ! is_array( $this->query_vars['post_type'] ) ) {
 				if ( ! in_array( $this->query_vars['post_type'], $queryable_post_types ) )