System.IO.Compression It does not work - Microsoft.Bcl.Compression

I've a xamarin form project, when i use this code
...
var re =await client.Execute(request);
var gs = new GZipStream(new MemoryStream(re.RawBytes), System.IO.Compression.CompressionMode.Decompress);
..

to call a web api service that return a compress GZipStream json but xamarin studio debug return me this
"The underlying implementation for System.IO.Compression.dll could not be loaded. Make sure to add a reference to the Microsoft.Bcl.Compression NuGet package from your main application project."

but in my project i've Microsoft.Bcl.Compression and i use FubarCoder.RestSharp.Portable

How can i risolve this problem ?

Thanks
Alex