Complains even when expected & found filename is the same

[sebbes333]

Error: Class file names should be based on the class name with "class-" prepended. Expected class-wpi-wpdb.php, but found class-wpi-wbdb.php.

File name: class-wpi-wbdb.php

Code in file:

<?php
class Wpi_Wpdb {
}

class-wpi-wpdb.php <--- EXPECTED class-wpi-wbdb.php <--- FOUND Difference = 0%