diff --git a/doc/api/zlib.md b/doc/api/zlib.md index 5575d03d330a8f..9fa9820f34618a 100644 --- a/doc/api/zlib.md +++ b/doc/api/zlib.md @@ -458,9 +458,12 @@ added: v0.5.8 Creates and returns a new [DeflateRaw][] object with the given [options][]. -*Note*: The zlib library rejects requests for 256-byte windows (i.e., -`{ windowBits: 8 }` in `options`). An `Error` will be thrown when creating -a [DeflateRaw][] object with this specific value of the `windowBits` option. +*Note*: An upgrade of zlib from 1.2.8 to 1.2.11 changed behavior when windowBits +is set to 8 for raw deflate streams. zlib would automatically set windowBits +to 9 if was initially set to 8. Newer versions of zlib will throw an exception, +so Node.js restored the original behavior of upgrading a value of 8 to 9, +since passing `windowBits = 9` to zlib actually results in a compressed stream +that effectively uses an 8-bit window only. ## zlib.createGunzip([options])