# Maintaining zlib This copy of zlib comes from the Chromium team's zlib fork which incorporated performance improvements not currently available in standard zlib. ## Updating zlib Update zlib: ```bash git clone https://chromium.googlesource.com/chromium/src/third_party/zlib cp deps/zlib/zlib.gyp deps/zlib/win32/zlib.def deps rm -rf deps/zlib zlib/.git mv zlib deps/ mv deps/zlib.gyp deps/zlib/ mkdir deps/zlib/win32 mv deps/zlib.def deps/zlib/win32 sed -i -- 's_^#include "chromeconf.h"_//#include "chromeconf.h"_' deps/zlib/zconf.h ``` Check that Node.js still builds and tests. It may be necessary to update deps/zlib/zlib.gyp if any significant changes have occurred upstream. ## Committing zlib Add zlib: `git add --all deps/zlib` Commit the changes with a message like ```text deps: update zlib to upstream d7f3ca9 Updated as described in doc/contributing/maintaining-zlib.md. ```