Transition on css background-size property doesn't work as expected on Chrome -

i searched , did test , found half of answer.

actually transition property doesn't work should (on chrome version 51.0.2704.106 m) on background-size when 1 value set, in case :

doesn't work:

.el {   background-size: 1200px;   transition: background-size .5s linear; }  .el:hover {   background-size: 1000px; }

works :

.el {   background-size: 1200px 1000px;   transition: background-size .5s linear; }  .el:hover {   background-size: 1000px 1000px; }

the problems if set second value background image distorted (which logic). second value can't auto (it doesn't work).

is there found solution?

please avoid : - forget prefixing, tested possible prefix.

here example (it works expected on mozilla firefox) : http://codepen.io/romaingranai/pen/pzjrdm

thank you

M16