Manually apply PR #2234
diff --git a/system/database/DB_query_builder.php b/system/database/DB_query_builder.php
index c7bc4a6..85a233b 100644
--- a/system/database/DB_query_builder.php
+++ b/system/database/DB_query_builder.php
@@ -2627,6 +2627,7 @@
 		$this->_reset_run(array(
 			'qb_set'	=> array(),
 			'qb_from'	=> array(),
+			'qb_join'	=> array(),
 			'qb_where'	=> array(),
 			'qb_orderby'	=> array(),
 			'qb_keys'	=> array(),