diff --git a/.buildkite/hooks/pre-command b/.buildkite/hooks/pre-command
new file mode 100644
index 00000000000..d3afdb6ed5e
--- /dev/null
+++ b/.buildkite/hooks/pre-command
@@ -0,0 +1,5 @@
+=======
+set -x
+
+NIX_PATH="nixpkgs=$(nix-build fetch-nixpkgs.nix -o nixpkgs)"
+export NIX_PATH
diff --git a/.buildkite/pipeline.yml b/.buildkite/pipeline.yml
index e0f45eb37f0..d58bd8de795 100644
--- a/.buildkite/pipeline.yml
+++ b/.buildkite/pipeline.yml
@@ -1,15 +1,15 @@
 steps:
   - label: 'stack2nix'
-    command: 'scripts/ci/nix-shell.sh -p cabal2nix stack cabal-install ghc moreutils expect -Q -j 4 --run scripts/check-stack2nix.sh'
+    command: 'nix-shell -Q -j 4 --run scripts/check-stack2nix.sh'
     agents:
       system: x86_64-linux
 
   - label: 'release.nix'
-    command: 'scripts/ci/nix-shell.sh --run scripts/ci/check-hydra.sh'
+    command: 'nix-shell --run scripts/ci/check-hydra.sh'
     agents:
       system: x86_64-linux
 
   - label: 'explorer frontend: checking generated dependencies'
-    command: 'scripts/ci/nix-shell.sh --run "cd explorer/frontend && ./nix/generate-frontend-deps.hs --test"'
+    command: "cd explorer/frontend && ./nix/generate-frontend-deps.hs --test"
     agents:
       system: x86_64-linux
diff --git a/pkgs/generate.sh b/pkgs/generate.sh
index bb8765a6cf3..8225cd84fce 100755
--- a/pkgs/generate.sh
+++ b/pkgs/generate.sh
@@ -1,5 +1,5 @@
 #!/usr/bin/env nix-shell
-#!nix-shell -i bash -p bash
+#!nix-shell -i bash -p bash cabal2nix stack cabal-install ghc
 
 # regenerate the `pkgs/default.nix` file based on the current contents of cardano-sl.cabal and stack.yaml
 
diff --git a/scripts/check-stack2nix.sh b/scripts/check-stack2nix.sh
index 5a4ebb3c14d..84435e7ed52 100755
--- a/scripts/check-stack2nix.sh
+++ b/scripts/check-stack2nix.sh
@@ -1,4 +1,5 @@
-#!/usr/bin/env bash
+#!/usr/bin/env nix-shell
+#!nix-shell -i bash -p git bash
 
 # check and warn if `pkgs/default.nix` is out of date
 
diff --git a/scripts/ci/nix-shell.sh b/scripts/ci/nix-shell.sh
deleted file mode 100755
index 23a2eb5e89d..00000000000
--- a/scripts/ci/nix-shell.sh
+++ /dev/null
@@ -1,27 +0,0 @@
-#!/bin/sh
-# sh is really bash in this case
-# shellcheck disable=SC2039
-
-set -x
-
-case $(uname -s | tr '[:upper:]' '[:lower:]') in
-        linux )  NIX_PROFILE_BINPATH=/run/current-system/sw/bin/;;
-        darwin ) NIX_PROFILE_BINPATH=/nix/var/nix/profiles/default/bin;;
-        * )      echo "Unsupported OS: $OS_NAME" >&2; exit 1;;
-esac
-
-# Bootstrap on OS X/NixOS:
-
-NIX_BUILD="$(type -P nix-build)"
-NIX_BUILD="${NIX_BUILD:-$NIX_PROFILE_BINPATH/nix-build}"
-NIX_SHELL="$(type -P nix-shell)"
-NIX_SHELL="${NIX_SHELL:-$NIX_PROFILE_BINPATH/nix-shell}"
-NIX_BUILD_SHELL="$(type -P bash)"
-NIX_BUILD_SHELL="${NIX_BUILD_SHELL:-$NIX_PROFILE_BINPATH/bash}"
-
-export NIX_REMOTE=daemon
-NIX_PATH="nixpkgs=$(${NIX_BUILD} fetch-nixpkgs.nix -o nixpkgs)"
-export NIX_PATH
-export NIX_BUILD_SHELL
-
-${NIX_SHELL} -p nix bash coreutils zlib gmp ncurses "$@"