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(),
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index 1b6cff1..216bf80 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -486,6 +486,7 @@
 -  Fixed a bug (#2211) - :doc:`Migration Library <libraries/migration>` extensions couldn't execute ``CI_Migration::__construct()``.
 -  Fixed a bug (#2255) - :doc:`Email Library <libraries/email>` didn't apply ``smtp_timeout``to socket reads and writes.
 -  Fixed a bug (#2239) - :doc:`Email Library <libraries/email>` improperly handled the Subject when used with ``bcc_batch_mode`` resulting in E_WARNING messages and an empty Subject.
+-  Fixed a bug (#2234) - :doc:`Query Builder <database/query_builder>` didn't reset JOIN cache for write-type queries.
 
 Version 2.1.3
 =============