# Bug report <!-- Before reporting an issue please check that you are using the latest PHPStan version! --> <!-- Please describe your problem here. --> Parameter `$keys` in `array_combine` should be `string[]` or `int[]` only. Every illegal data type will be converted to string. ### Code snippet that reproduces the problem <!-- Try to reproduce the issue you are facing using https://phpstan.org/ and post the unique URL here --> https://phpstan.org/r/2b7e973c-2157-49dd-a4d1-3806a9688293 https://3v4l.org/lRn5W ### Expected output Should report errors. <!-- Was the issue reported incorrectly? Or should PHPStan detect an issue with the code but doesn't? -->