diff --git a/ansible/README.md b/ansible/README.md
index 9484d5b..51e668e 100644
--- a/ansible/README.md
+++ b/ansible/README.md
@@ -2,10 +2,10 @@
 
 ## Ansible Control Node Setup
 
-In a Python 3 environment (perhaps a venv):
+Run in repository root to use `ansible-*` commands:
 
 ```
-pip install -r requirements.txt
+nix run -c $SHELL
 ```
 
 ## `misc.yaml`
diff --git a/default.nix b/default.nix
new file mode 100644
index 0000000..80de056
--- /dev/null
+++ b/default.nix
@@ -0,0 +1,13 @@
+{
+  pkgs ? import <nixpkgs> {}
+}:
+let
+  paths = with pkgs; [
+    ansible
+    ansible-lint
+  ];
+in
+  pkgs.buildEnv {
+    name = "infrastructure-env";
+    paths = paths;
+  }