Index: wp-includes/query.php
===================================================================
--- wp-includes/query.php	(revision 12445)
+++ wp-includes/query.php	(working copy)
@@ -1163,6 +1163,9 @@
 			, 'meta_key'
 			, 'meta_value'
 			, 'preview'
+			, 's'
+			, 'search_terms'
+			, 'sentence'
 		);
 
 		foreach ($keys as $key) {