diff --git a/pkgs/development/libraries/libz/default.nix b/pkgs/development/libraries/libz/default.nix
new file mode 100644
index 00000000000..6b3e1dacdc0
--- /dev/null
+++ b/pkgs/development/libraries/libz/default.nix
@@ -0,0 +1,30 @@
+{ lib
+, stdenv
+, fetchFromGitLab
+, unstableGitUpdater
+}:
+
+stdenv.mkDerivation (finalAttrs: {
+  pname = "libz";
+  version = "unstable-2018-03-31";
+
+  src = fetchFromGitLab {
+    owner = "sortix";
+    repo = "libz";
+    rev = "752c1630421502d6c837506d810f7918ac8cdd27";
+    hash = "sha256-AQuZ0BOl1iP5Nub+tVwctlE2tfJe4Sq/KDGkjwBbsV4=";
+  };
+
+  outputs = [ "out" "dev" ];
+  outputDoc = "dev"; # single tiny man3 page
+
+  passthru.updateScript = unstableGitUpdater { };
+
+  meta = {
+    homepage = "https://sortix.org/libz/";
+    description = "A clean fork of zlib";
+    license = [ lib.licenses.zlib ];
+    maintainers = with lib.maintainers; [ AndersonTorres ];
+    platforms = lib.platforms.unix;
+  };
+})
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 4f31b446252..3dd200d9659 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -5768,6 +5768,8 @@ with pkgs;
 
   libxnd = callPackage ../development/libraries/libxnd { };
 
+  libz = callPackage ../development/libraries/libz { };
+
   libzbc = callPackage ../os-specific/linux/libzbc { };
 
   libzbd = callPackage ../os-specific/linux/libzbd { };