diff --git a/flake.lock b/flake.lock
index 37c2d2133a9..ce3e96c6779 100644
--- a/flake.lock
+++ b/flake.lock
@@ -801,7 +801,11 @@
         "iohk-nix": "iohk-nix",
         "nixpkgs": [
           "haskell-nix",
-          "nixpkgs-unstable"
+          "nixpkgs"
+        ],
+        "nixpkgs-2405": [
+          "haskell-nix",
+          "nixpkgs-2405"
         ],
         "pre-commit-hooks": "pre-commit-hooks"
       }
diff --git a/flake.nix b/flake.nix
index 30942c01cd7..edcb8048b7e 100644
--- a/flake.nix
+++ b/flake.nix
@@ -2,7 +2,9 @@
   description = "Plutus Core";
 
   inputs = {
-    nixpkgs.follows = "haskell-nix/nixpkgs-unstable";
+    nixpkgs-2405.follows = "haskell-nix/nixpkgs-2405";
+
+    nixpkgs.follows = "haskell-nix/nixpkgs";
 
     hackage = {
       url = "github:input-output-hk/hackage.nix";
diff --git a/nix/metatheory-site.nix b/nix/metatheory-site.nix
index 489b70cda04..199dbfb1e5c 100644
--- a/nix/metatheory-site.nix
+++ b/nix/metatheory-site.nix
@@ -1,7 +1,7 @@
 # This file evaluates to a derivation that builds the AGDA metatheory
 # documentation site using Jekyll. The derivation also checks for broken links
 # in the generated HTML.
-{ self, pkgs, lib, agda-with-stdlib }:
+{ inputs, self, pkgs, lib, agda-with-stdlib }:
 
 let
 
@@ -37,7 +37,7 @@ let
     {
       buildInputs = [
         pkgs.jekyll
-        pkgs.linkchecker
+        inputs.nixpkgs-2405.legacyPackages.${pkgs.system}.linkchecker
       ];
     } ''
     mkdir "$out"
diff --git a/nix/outputs.nix b/nix/outputs.nix
index 8a5975d5cca..ad7ce69ddc1 100644
--- a/nix/outputs.nix
+++ b/nix/outputs.nix
@@ -30,7 +30,7 @@ let
     { inherit self build-latex-doc; };
 
   metatheory-site = import ./metatheory-site.nix
-    { inherit self pkgs lib agda-with-stdlib; };
+    { inherit inputs self pkgs lib agda-with-stdlib; };
 
   project = import ./project.nix
     { inherit inputs pkgs lib agda-with-stdlib r-with-packages; };
diff --git a/nix/shell.nix b/nix/shell.nix
index db8e9946f14..4e5c2d0f113 100644
--- a/nix/shell.nix
+++ b/nix/shell.nix
@@ -70,6 +70,7 @@ let
   common-pkgs = [
     agda-with-stdlib
     r-with-packages
+    inputs.nixpkgs-2405.legacyPackages.${pkgs.system}.linkchecker
 
     pkgs.texliveFull
     pkgs.jekyll
@@ -93,7 +94,7 @@ let
     pkgs.git
     pkgs.which
     pkgs.nodejs_20
-    pkgs.linkchecker
+
   ];
 
 in