Fix #3242
diff --git a/system/database/DB_query_builder.php b/system/database/DB_query_builder.php
index 4e37e4c..4b3aa4d 100644
--- a/system/database/DB_query_builder.php
+++ b/system/database/DB_query_builder.php
@@ -664,7 +664,7 @@
 			else
 			{
 				$operator = $this->_get_operator($k);
-				if (stripos($operator, 'NULL') === FALSE)
+				if (stripos($operator, 'NULL') === FALSE && strncasecmp(ltrim($operator), 'IN', 2) !== 0)
 				{
 					$op = strrpos($k, $operator);
 					if (strlen($k) === ($op + strlen($operator)))