diff --git a/.envrc b/.envrc
index 5a4cf11..72617b2 100644
--- a/.envrc
+++ b/.envrc
@@ -1,3 +1,5 @@
+use nix
+
 export TODO_FILE=$PWD/TODO
 
 todo.sh ls || :
diff --git a/shell.nix b/shell.nix
new file mode 100644
index 0000000..997ed45
--- /dev/null
+++ b/shell.nix
@@ -0,0 +1,5 @@
+{ pkgs ? import <nixpkgs> {} }:
+with pkgs;
+mkShell {
+  buildInputs = with python3Packages; [ Mako requests ];
+}