diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c1ede85eb2..512abe240c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -26,7 +26,7 @@ jobs:
           - name: Linux release
             os: ubuntu-latest
             release: true
-            shell: nix-shell --arg glibc "(import (fetchTarball \"channel:nixos-19.03\") {{}}).glibc" --run "bash -euxo pipefail {0}"
+            shell: nix-shell --arg pkgsDist "import (fetchTarball \"channel:nixos-19.03\") {{}}" --run "bash -euxo pipefail {0}"
             llvm-url: https://github.com/leanprover/lean-llvm/releases/download/13.0.0/lean-llvm-x86_64-linux-gnu.tar.zst
           - name: Linux
             os: ubuntu-latest
diff --git a/script/prepare-llvm-linux.sh b/script/prepare-llvm-linux.sh
index 43086958a6..c54c7f7759 100755
--- a/script/prepare-llvm-linux.sh
+++ b/script/prepare-llvm-linux.sh
@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 set -uo pipefail
 
-# run from root build directory (from inside nix-shell or otherwise defining GLIBC/GMP) as in
+# run from root build directory (from inside nix-shell or otherwise defining GLIBC/ZLIB/GMP) as in
 # ```
 # eval cmake ../.. $(../../script/prepare-llvm-linux.sh ~/Downloads/clang+llvm-13.0.0-x86_64-linux-gnu-ubuntu-16.04.tar.xz)
 # ```
@@ -14,9 +14,10 @@ CP="cp -d"  # preserve symlinks
 # a C compiler!
 $CP $(realpath llvm/bin/clang) stage1/bin/clang
 # a linker!
-$CP llvm/bin/{lld,ld.lld} stage1/bin/
+$CP llvm/bin/{ld.lld,lld} stage1/bin/
 # dependencies of the above
 $CP llvm/lib/lib{clang-cpp,LLVM}*.so* stage1/lib/
+$CP $ZLIB/lib/libz.so* stage1/lib/
 # lean.h dependencies
 $CP llvm/lib/clang/*/include/{std*,__std*,limits}.h stage1/include/clang
 # ELF dependencies, must be put there for `--sysroot`
diff --git a/shell.nix b/shell.nix
index 73d2625e63..6d5bb1de6e 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,6 +1,6 @@
 let
   flakePkgs = (import ./default.nix).packages.${builtins.currentSystem};
-in { pkgs ? flakePkgs.nixpkgs, llvmPackages ? null, glibc ? pkgs.glibc }:
+in { pkgs ? flakePkgs.nixpkgs, pkgsDist ? pkgs, llvmPackages ? null }:
 # use `shell` as default
 (attribs: attribs.shell // attribs) rec {
   shell = pkgs.mkShell.override {
@@ -13,8 +13,9 @@ in { pkgs ? flakePkgs.nixpkgs, llvmPackages ? null, glibc ? pkgs.glibc }:
     hardeningDisable = [ "all" ];
     # more convenient `ctest` output
     CTEST_OUTPUT_ON_FAILURE = 1;
-    GMP = pkgs.gmp.override { withStatic = true; };
-    GLIBC = glibc;
+    GMP = pkgsDist.gmp.override { withStatic = true; };
+    GLIBC = pkgsDist.glibc;
+    ZLIB = pkgsDist.zlib;
     shellHook = ''
       export LEAN_SRC_PATH="$PWD/src"
     '';