diff --git a/system/database/DB_query_builder.php b/system/database/DB_query_builder.php
index 978fc6a..ac377d9 100644
--- a/system/database/DB_query_builder.php
+++ b/system/database/DB_query_builder.php
@@ -1202,7 +1202,7 @@
 	 */
 	public function limit($value, $offset = FALSE)
 	{
-		$value === NULL OR $this->qb_limit = (int) $value;
+		is_null($value) OR $this->qb_limit = (int) $value;
 		empty($offset) OR $this->qb_offset = (int) $offset;
 
 		return $this;