diff --git a/peering b/peering
index 98e4251..4db9f38 100755
--- a/peering
+++ b/peering
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -eu
 
 progdir=$(cd "$(dirname "$0")" && pwd -P)
diff --git a/scripts/peering-app b/scripts/peering-app
index e1c43c8..a3bd006 100755
--- a/scripts/peering-app
+++ b/scripts/peering-app
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -eu
 
 usage () {
diff --git a/scripts/peering-bgp b/scripts/peering-bgp
index a98caef..c1c2748 100755
--- a/scripts/peering-bgp
+++ b/scripts/peering-bgp
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -eu
 
 usage () {
diff --git a/scripts/peering-openvpn b/scripts/peering-openvpn
index 019ddbf..0d8e530 100755
--- a/scripts/peering-openvpn
+++ b/scripts/peering-openvpn
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -eu
 
 usage () {
diff --git a/scripts/peering-prefix b/scripts/peering-prefix
index 32c0182..cc10a30 100755
--- a/scripts/peering-prefix
+++ b/scripts/peering-prefix
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -eu
 
 # program=$(basename $0)
diff --git a/scripts/peering-proxy b/scripts/peering-proxy
index d34dbfc..ecff16a 100755
--- a/scripts/peering-proxy
+++ b/scripts/peering-proxy
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -eu
 
 usage () {
diff --git a/shell.nix b/shell.nix
new file mode 100644
index 0000000..3cb6995
--- /dev/null
+++ b/shell.nix
@@ -0,0 +1,11 @@
+{ pkgs ? import <nixpkgs> {}}:
+
+pkgs.mkShell {
+  buildInputs = with pkgs; [
+    bird2
+    openvpn
+    socat
+    psmisc
+    ipcalc
+  ];
+}