diff --git a/source/guides/recipes/dependency-management.md b/source/guides/recipes/dependency-management.md
index ee40204..cac6f18 100644
--- a/source/guides/recipes/dependency-management.md
+++ b/source/guides/recipes/dependency-management.md
@@ -7,10 +7,10 @@ Nix expressions themselves can depend on remote sources, and there are multiple
 For more automation around handling remote sources, set up [niv](https://github.com/nmattia/niv/) in your project:
 
 ```shell-session
-$ nix-shell -p niv --run "niv init --nixpkgs nixos/nixpkgs --nixpkgs-branch nixos-23.05"
+$ nix-shell -p niv --run "niv init --nixpkgs nixos/nixpkgs --nixpkgs-branch nixos-23.11"
 ```
 
-This command will fetch the latest revision of the Nixpkgs 23.05 release branch.
+This command will fetch the latest revision of the Nixpkgs 23.11 release branch.
 In the current directory it will generate `nix/sources.json`, which will contain a pinned reference to the obtained revision.
 It will also create `nix/sources.nix`, which exposes those dependencies as an attribute set.
 
@@ -66,7 +66,7 @@ Enter the development environment, create a new directory, and set up niv with a
 $ nix-shell
 [nix-shell]$ mkdir old
 [nix-shell]$ cd old
-[nix-shell]$ niv init --nixpkgs nixos/nixpkgs --nixpkgs-branch 18.09
+[nix-shell]$ niv init --nixpkgs nixos/nixpkgs --nixpkgs-branch 21.11
 ```
 
 Create a file `default.nix` in the new directory, and import the original one with the `sources` just created.
diff --git a/source/guides/recipes/direnv.md b/source/guides/recipes/direnv.md
index aab64df..63c6ba0 100644
--- a/source/guides/recipes/direnv.md
+++ b/source/guides/recipes/direnv.md
@@ -10,7 +10,7 @@ For example, write a `shell.nix` with the following contents:
 
 ```nix
 let
-  nixpkgs = fetchTarball "https://github.com/NixOS/nixpkgs/tarball/nixos-22.11";
+  nixpkgs = fetchTarball "https://github.com/NixOS/nixpkgs/tarball/nixos-23.11";
   pkgs = import nixpkgs { config = {}; overlays = []; };
 in
 
@@ -19,8 +19,8 @@ pkgs.mkShellNoCC {
     hello
   ];
 }
-
 ```
+
 From the top-level directory of your project run:
 
 ```shell-session
@@ -41,7 +41,7 @@ Make the following addition:
 
 ```diff
  let
-   nixpkgs = fetchTarball "https://github.com/NixOS/nixpkgs/tarball/nixos-22.11";
+   nixpkgs = fetchTarball "https://github.com/NixOS/nixpkgs/tarball/nixos-23.11";
    pkgs = import nixpkgs { config = {}; overlays = []; };
  in
 
diff --git a/source/guides/recipes/python-environment.md b/source/guides/recipes/python-environment.md
index 87bd260..7bd9c13 100644
--- a/source/guides/recipes/python-environment.md
+++ b/source/guides/recipes/python-environment.md
@@ -31,7 +31,7 @@ This is a simple Flask application which serves a JSON document with the message
 Create a new file `shell.nix` to declare the development environment:
 
 ```{code-block} nix shell.nix
-{ pkgs ? import (fetchTarball "https://github.com/NixOS/nixpkgs/tarball/nixos-22.11") {} }:
+{ pkgs ? import (fetchTarball "https://github.com/NixOS/nixpkgs/tarball/nixos-23.11") {} }:
 
 pkgs.mkShellNoCC {
   packages = with pkgs; [
diff --git a/source/guides/recipes/sharing-dependencies.md b/source/guides/recipes/sharing-dependencies.md
index 4d44af2..099e530 100644
--- a/source/guides/recipes/sharing-dependencies.md
+++ b/source/guides/recipes/sharing-dependencies.md
@@ -49,7 +49,7 @@ Further assume your project is defined in `default.nix`:
 ```nix
 # default.nix
 let
-  nixpkgs = fetchTarball "https://github.com/NixOS/nixpkgs/tarball/nixos-22.11";
+  nixpkgs = fetchTarball "https://github.com/NixOS/nixpkgs/tarball/nixos-23.11";
   pkgs = import nixpkgs { config = {}; overlays = []; };
 in
 {
@@ -62,7 +62,7 @@ Add an attribute to `default.nix` specifying an environment:
 
 ```diff
  let
-   nixpkgs = fetchTarball "https://github.com/NixOS/nixpkgs/tarball/nixos-22.11";
+   nixpkgs = fetchTarball "https://github.com/NixOS/nixpkgs/tarball/nixos-23.11";
    pkgs = import nixpkgs { config = {}; overlays = []; };
  in
  {
@@ -77,7 +77,7 @@ Then take the package's dependencies into the environment with [`inputsFrom`](ht
 
 ```diff
  let
-   nixpkgs = fetchTarball "https://github.com/NixOS/nixpkgs/tarball/nixos-22.11";
+   nixpkgs = fetchTarball "https://github.com/NixOS/nixpkgs/tarball/nixos-23.11";
    pkgs = import nixpkgs { config = {}; overlays = []; };
 +  build = pkgs.callPackage ./build.nix {};
  in