'phpspec' is not recognized as an internal or external command, operable program or batch file

I'm using Windows. I installed phpspec package with composer, I added the folder phpspec/bin/ to my system's path variable. But when I try to run phpspec command I get the following error:

'phpspec' is not recognized as an internal or external command,
operable program or batch file.

Even when I run the command directly from the bin directory where the phpspec.php is stored, I get the same error.