@extend not working in media queries

[alextekartik]

While @extend works fine and suit some if my needs, it is not working correctly within @media query block. Let's assume the following css

.good { color: red; } 
@media screen {
  .better { @extend .good; } 
}

It should generate

.good { color: red; } 
@media screen { .better { color: red; } }

so that .better definition is only valid within the media query. However it generates:

.good, .better { color: red; } 
@media screen { .better { } }';

ignoring the media query

Unit test available here