Chunked transfer encoding + gzip

I'm writing a content filter for squid using eCAP.
I successfuly parse gzipped streams and uncompressed streams, but when it's chunked + gzip, the chunks that arrive as virgin bytes are not a valid gzip stream when combined, i.e. when passed to z stream same way as I pass them for non-chunked cases.

I've looked at raw virgin bytes caught in Fiddler and in the code, and it seems that content comes de-chunked. Or the chunks are split too. What does adapter recieve in case of chunked encoding?