css - transition with -webkit- transform in shorthand rule -

i have grunt postcss running autoprefixer, , code:

transition: transform .3s, color .3s; 

... outputting:

transition: color .3s, -webkit-transform .3s; transition: transform .3s, color .3s; transition: transform .3s, color .3s, -webkit-transform .3s; 

but shouldn't outputting this?

-webkit-transition: -webkit-transform .3s, color .3s; transition: transform .3s, color .3s; 

my postcss settings are:

postcss: {     options: {         map: {             inline: false, // save sourcemaps separate files...             annotation: '../css/' // ...to specified directory         },          processors: [             require('autoprefixer')({browsers: 'last 2 versions'}), // add vendor prefixes         ]     },     dist: {         src: '../css/*.css'     } } 

i have no idea if i'm doing wrong, if it's outputting incorrectly, or if it's correct.

thanks

you have write correct css, not fault, can check css on official page, , according browser selection setting {browsers: 'last 2 versions'} don't need transition prefix last 2 webkit versions, generated css correct.