diff --git a/system/database/drivers/oci8/oci8_driver.php b/system/database/drivers/oci8/oci8_driver.php
index bc0862b..99f7d57 100644
--- a/system/database/drivers/oci8/oci8_driver.php
+++ b/system/database/drivers/oci8/oci8_driver.php
@@ -393,7 +393,7 @@
 	function insert_id()
 	{
 		// not supported in oracle
-		return 0;
+		return $this->display_error('db_unsupported_function');
 	}
 
 	// --------------------------------------------------------------------