diff --git a/lib/tests/release.nix b/lib/tests/release.nix
index 5b2a9df1635c..1447e8817091 100644
--- a/lib/tests/release.nix
+++ b/lib/tests/release.nix
@@ -2,7 +2,7 @@
   # Don't test properties of pkgs.lib, but rather the lib in the parent directory
   pkgs ? import ../.. {} // { lib = throw "pkgs.lib accessed, but the lib tests should use nixpkgs' lib path directly!"; },
   nix ? pkgs-nixVersions.stable,
-  nixVersions ? [ pkgs-nixVersions.minimum nix pkgs-nixVersions.unstable ],
+  nixVersions ? [ pkgs-nixVersions.minimum nix pkgs-nixVersions.latest ],
   pkgs-nixVersions ? import ./nix-for-tests.nix { inherit pkgs; },
 }:
 
diff --git a/nixos/doc/manual/release-notes/rl-2405.section.md b/nixos/doc/manual/release-notes/rl-2405.section.md
index d83e7c4ff71c..9dfcc4b373b2 100644
--- a/nixos/doc/manual/release-notes/rl-2405.section.md
+++ b/nixos/doc/manual/release-notes/rl-2405.section.md
@@ -30,6 +30,10 @@ In addition to numerous new and upgraded packages, this release has the followin
 
   To disable this, set [nixpkgs.flake.setNixPath](#opt-nixpkgs.flake.setNixPath) and [nixpkgs.flake.setFlakeRegistry](#opt-nixpkgs.flake.setFlakeRegistry) to false.
 
+- `nixVersions.unstable` was removed. Instead the following attributes are provided:
+  - `nixVersions.git` which tracks the latest Nix master and is roughly updated once a week. This is intended to enable people to easily test unreleased changes of Nix to catch regressions earlier.
+  - `nixVersions.latest` which points to the latest Nix version packaged in nixpkgs.
+
 - Julia environments can now be built with arbitrary packages from the ecosystem using the `.withPackages` function. For example: `julia.withPackages ["Plots"]`.
 
 - The PipeWire and WirePlumber modules have removed support for using
diff --git a/pkgs/development/tools/language-servers/nil/default.nix b/pkgs/development/tools/language-servers/nil/default.nix
index 19822d2977fc..88d4a6fd3668 100644
--- a/pkgs/development/tools/language-servers/nil/default.nix
+++ b/pkgs/development/tools/language-servers/nil/default.nix
@@ -14,7 +14,7 @@ rustPlatform.buildRustPackage rec {
   cargoHash = "sha256-lyKPmzuZB9rCBI9JxhxlyDtNHLia8FXGnSgV+D/dwgo=";
 
   nativeBuildInputs = [
-    (lib.getBin nixVersions.unstable)
+    (lib.getBin nixVersions.latest)
   ];
 
   env.CFG_RELEASE = version;
diff --git a/pkgs/tools/package-management/nix/default.nix b/pkgs/tools/package-management/nix/default.nix
index 3eb49fb62b3d..1522f141da7c 100644
--- a/pkgs/tools/package-management/nix/default.nix
+++ b/pkgs/tools/package-management/nix/default.nix
@@ -179,6 +179,19 @@ in lib.makeExtensible (self: ({
     hash = "sha256-Ugcc+lSq8nJP+mddMlGFnoG4Ix1lRFHWOal3299bqR8=";
   };
 
+  git = common rec {
+    version = "2.22.0";
+    suffix = "pre20240421_${lib.substring 0 8 src.rev}";
+    src = fetchFromGitHub {
+      owner = "NixOS";
+      repo = "nix";
+      rev = "6fd2f42c2defd210e17ec95653110fc58858dba9";
+      hash = "sha256-DjkxYMcG52APiADdEtXL1FNVSxNXRBw78LYctly93j0=";
+    };
+  };
+
+  latest = self.nix_2_21;
+
   # The minimum Nix version supported by Nixpkgs
   # Note that some functionality *might* have been backported into this Nix version,
   # making this package an inaccurate representation of what features are available
@@ -197,8 +210,6 @@ in lib.makeExtensible (self: ({
       nix;
 
   stable = addFallbackPathsCheck self.nix_2_18;
-
-  unstable = self.nix_2_22;
 } // lib.optionalAttrs config.allowAliases (
   lib.listToAttrs (map (
     minor:
@@ -207,4 +218,7 @@ in lib.makeExtensible (self: ({
     in
     lib.nameValuePair attr (throw "${attr} has been removed")
   ) (lib.range 4 17))
+  // {
+    unstable = throw "nixVersions.unstable has been removed. For bleeding edge (Nix master, roughly weekly updated) use nixVersions.git, otherwise use nixVersions.latest.";
+  }
 )))