diff --git a/README.md b/README.md
index 9d34490..19abc58 100644
--- a/README.md
+++ b/README.md
@@ -13,6 +13,14 @@ NOTE: Instructions are written with the assumption that the command `python` poi
 
 ### NixOS
 
+```
+nix-shell
+python pomodoroprompt.py
+```
+...or:  
+`alias pom="nix-shell --command 'python pomodoroprompt.py'`
+
+You need not install Python (and it is not recommended). Should you insist, this may be correct:
 ```
 python
 python311Packages.playsound
@@ -20,6 +28,8 @@ python311Packages.pycairo
 python311Packages.pygobject3
 python311Packages.pytz
 python311Packages.tzlocal
+wrapGAppsHook
+gobject-introspection
 ```
 
 (And skip the last two lines below, the pip install, as the above is the Nix way of doing that.)
diff --git a/shell.nix b/shell.nix
new file mode 100644
index 0000000..484bf23
--- /dev/null
+++ b/shell.nix
@@ -0,0 +1,22 @@
+# shell.nix
+let
+  # We pin to a specific nixpkgs commit for reproducibility.
+  # Last updated: 2024-04-29. Check for new commits at https://status.nixos.org.
+  pkgs = import (fetchTarball "https://github.com/NixOS/nixpkgs/archive/aebe249544837ce42588aa4b2e7972222ba12e8f.tar.gz") {};
+in pkgs.mkShell {
+  packages = [
+    (pkgs.python3.withPackages (python-pkgs: with python-pkgs; [
+      # select Python packages here
+      playsound
+      pycairo
+      pytz
+      tzlocal
+      # For Qt:
+      # pyside6
+      # Using GTK:
+      pygobject3
+    ]))
+    pkgs.wrapGAppsHook
+    pkgs.gobject-introspection
+  ];
+}