Vintage windbreaker size S

I love this windbreaker so much I think it looks really cool. It is not so much of a windbreaker as the material is thin and kind of more like canvas(?). The material has absolutely no stretch to it. When I wore this as a size medium, it was quite tight on my hips, as in the draw string was essentially useless. This jacket would fit a small better. Originally got this at thrift store. There is no brand or size associated with this jacket.