diff --git a/flake.lock b/flake.lock
index 66508f26d..d47f55846 100644
--- a/flake.lock
+++ b/flake.lock
@@ -202,43 +202,6 @@
         "type": "github"
       }
     },
-    "ghc910X": {
-      "flake": false,
-      "locked": {
-        "lastModified": 1714520650,
-        "narHash": "sha256-4uz6RA1hRr0RheGNDM49a/B3jszqNNU8iHIow4mSyso=",
-        "ref": "ghc-9.10",
-        "rev": "2c6375b9a804ac7fca1e82eb6fcfc8594c67c5f5",
-        "revCount": 62663,
-        "submodules": true,
-        "type": "git",
-        "url": "https://gitlab.haskell.org/ghc/ghc"
-      },
-      "original": {
-        "ref": "ghc-9.10",
-        "submodules": true,
-        "type": "git",
-        "url": "https://gitlab.haskell.org/ghc/ghc"
-      }
-    },
-    "ghc911": {
-      "flake": false,
-      "locked": {
-        "lastModified": 1714817013,
-        "narHash": "sha256-m2je4UvWfkgepMeUIiXHMwE6W+iVfUY38VDGkMzjCcc=",
-        "ref": "refs/heads/master",
-        "rev": "fc24c5cf6c62ca9e3c8d236656e139676df65034",
-        "revCount": 62816,
-        "submodules": true,
-        "type": "git",
-        "url": "https://gitlab.haskell.org/ghc/ghc"
-      },
-      "original": {
-        "submodules": true,
-        "type": "git",
-        "url": "https://gitlab.haskell.org/ghc/ghc"
-      }
-    },
     "gitignore": {
       "inputs": {
         "nixpkgs": [
@@ -285,8 +248,6 @@
         "cardano-shell": "cardano-shell",
         "flake-compat": "flake-compat_2",
         "ghc-8.6.5-iohk": "ghc-8.6.5-iohk",
-        "ghc910X": "ghc910X",
-        "ghc911": "ghc911",
         "hackage": [
           "hackageNix"
         ],
@@ -299,6 +260,7 @@
         "hls-2.6": "hls-2.6",
         "hls-2.7": "hls-2.7",
         "hls-2.8": "hls-2.8",
+        "hls-2.9": "hls-2.9",
         "hpc-coveralls": "hpc-coveralls",
         "hydra": "hydra",
         "iserv-proxy": "iserv-proxy",
@@ -313,21 +275,21 @@
         "nixpkgs-2211": "nixpkgs-2211",
         "nixpkgs-2305": "nixpkgs-2305",
         "nixpkgs-2311": "nixpkgs-2311",
+        "nixpkgs-2405": "nixpkgs-2405",
         "nixpkgs-unstable": "nixpkgs-unstable",
         "old-ghc-nix": "old-ghc-nix",
         "stackage": "stackage"
       },
       "locked": {
-        "lastModified": 1718797200,
-        "narHash": "sha256-ueFxTuZrQ3ZT/Fj5sSeUWlqKa4+OkUU1xW0E+q/XTfw=",
+        "lastModified": 1730432803,
+        "narHash": "sha256-TL//ooWXQTObYE693t1aagyRJAGWNkcQhCA3tWO/4As=",
         "owner": "input-output-hk",
         "repo": "haskell.nix",
-        "rev": "cb139fa956158397aa398186bb32dd26f7318784",
+        "rev": "3a2662401d82a33a30582e17f1e94bfaf16d6424",
         "type": "github"
       },
       "original": {
         "owner": "input-output-hk",
-        "ref": "cb139fa956158397aa398186bb32dd26f7318784",
         "repo": "haskell.nix",
         "type": "github"
       }
@@ -485,6 +447,23 @@
         "type": "github"
       }
     },
+    "hls-2.9": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1720003792,
+        "narHash": "sha256-qnDx8Pk0UxtoPr7BimEsAZh9g2WuTuMB/kGqnmdryKs=",
+        "owner": "haskell",
+        "repo": "haskell-language-server",
+        "rev": "0c1817cb2babef0765e4e72dd297c013e8e3d12b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "haskell",
+        "ref": "2.9.0.1",
+        "repo": "haskell-language-server",
+        "type": "github"
+      }
+    },
     "hpc-coveralls": {
       "flake": false,
       "locked": {
@@ -697,11 +676,11 @@
     },
     "nixpkgs-2305": {
       "locked": {
-        "lastModified": 1701362232,
-        "narHash": "sha256-GVdzxL0lhEadqs3hfRLuj+L1OJFGiL/L7gCcelgBlsw=",
+        "lastModified": 1705033721,
+        "narHash": "sha256-K5eJHmL1/kev6WuqyqqbS1cdNnSidIZ3jeqJ7GbrYnQ=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "d2332963662edffacfddfad59ff4f709dde80ffe",
+        "rev": "a1982c92d8980a0114372973cbdfe0a307f1bdea",
         "type": "github"
       },
       "original": {
@@ -713,11 +692,11 @@
     },
     "nixpkgs-2311": {
       "locked": {
-        "lastModified": 1701386440,
-        "narHash": "sha256-xI0uQ9E7JbmEy/v8kR9ZQan6389rHug+zOtZeZFiDJk=",
+        "lastModified": 1719957072,
+        "narHash": "sha256-gvFhEf5nszouwLAkT9nWsDzocUTqLWHuL++dvNjMp9I=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "293822e55ec1872f715a66d0eda9e592dc14419f",
+        "rev": "7144d6241f02d171d25fba3edeaf15e0f2592105",
         "type": "github"
       },
       "original": {
@@ -727,6 +706,22 @@
         "type": "github"
       }
     },
+    "nixpkgs-2405": {
+      "locked": {
+        "lastModified": 1726447378,
+        "narHash": "sha256-2yV8nmYE1p9lfmLHhOCbYwQC/W8WYfGQABoGzJOb1JQ=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "086b448a5d54fd117f4dc2dee55c9f0ff461bdc1",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-24.05-darwin",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
     "nixpkgs-regression": {
       "locked": {
         "lastModified": 1643052045,
@@ -761,17 +756,17 @@
     },
     "nixpkgs-unstable": {
       "locked": {
-        "lastModified": 1694822471,
-        "narHash": "sha256-6fSDCj++lZVMZlyqOe9SIOL8tYSBz1bI8acwovRwoX8=",
+        "lastModified": 1726583932,
+        "narHash": "sha256-zACxiQx8knB3F8+Ze+1BpiYrI+CbhxyWpcSID9kVhkQ=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "47585496bcb13fb72e4a90daeea2f434e2501998",
+        "rev": "658e7223191d2598641d50ee4e898126768fe847",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
         "repo": "nixpkgs",
-        "rev": "47585496bcb13fb72e4a90daeea2f434e2501998",
         "type": "github"
       }
     },
@@ -897,11 +892,11 @@
     "stackage": {
       "flake": false,
       "locked": {
-        "lastModified": 1718756571,
-        "narHash": "sha256-8rL8viTbuE9/yV1of6SWp2tHmhVMD2UmkOfmN5KDbKg=",
+        "lastModified": 1730419934,
+        "narHash": "sha256-JJ85fnFBsUTCQOUIn82nlFlWgsrruvtFwKfc4LCCCJs=",
         "owner": "input-output-hk",
         "repo": "stackage.nix",
-        "rev": "027672fb6fd45828b0e623c8152572d4058429ad",
+        "rev": "2c63b809f462ee4043dda25cb0b2998eaa3b9bd2",
         "type": "github"
       },
       "original": {
diff --git a/flake.nix b/flake.nix
index 37292f3bd..e8d28a7f7 100644
--- a/flake.nix
+++ b/flake.nix
@@ -2,8 +2,7 @@
   description = "cardano-base";
 
   inputs = {
-    # freeze haskell.nix prior to the nixpkgs update that broken 8.10 cross-windows
-    haskellNix.url = "github:input-output-hk/haskell.nix?ref=cb139fa956158397aa398186bb32dd26f7318784";
+    haskellNix.url = "github:input-output-hk/haskell.nix";
     # allow us to independently update hackageNix
     haskellNix.inputs.hackage.follows = "hackageNix";
     nixpkgs.follows = "haskellNix/nixpkgs-unstable";
@@ -56,7 +55,7 @@
         inherit (nixpkgs) lib;
 
         # see flake `variants` below for alternative compilers
-        defaultCompiler = "ghc964";
+        defaultCompiler = "ghc966";
         fourmoluVersion = "0.16.2.0";
         # We use cabalProject' to ensure we don't build the plan for
         # all systems.
@@ -112,11 +111,23 @@
             # Skip cross compilers for the shell
             crossPlatforms = _: [];
           };
+          flake = {
+            # on linux, build/test other supported compilers
+            variants = lib.genAttrs ["ghc8107"] (compiler-nix-name: {
+              inherit compiler-nix-name;
+            });
+            # we also want cross compilation to windows.
+            crossPlatforms = p: lib.optional (system == "x86_64-linux" && config.compiler-nix-name != "ghc8107") p.mingwW64;
+          };
 
           # package customizations as needed. Where cabal.project is not
           # specific enough, or doesn't allow setting these.
           modules = [
             ({pkgs, ...}: {
+              # Packages that are not always in the plan need to be listed so that haskell.nix does not
+              # complain about overrides on packages that do not exist.
+              package-keys = ["katip" "ekg" "slotting" "lens" "nonempty-vector"];
+
               # Packages we wish to ignore version bounds of.
               # This is similar to jailbreakCabal, however it
               # does not require any messing with cabal files.
@@ -148,17 +159,7 @@
           ];
         });
         # ... and construct a flake from the cabal project
-        flake =
-          cabalProject.flake (
-            lib.optionalAttrs (system == "x86_64-linux") {
-              # on linux, build/test other supported compilers
-              variants = lib.genAttrs ["ghc8107"] (compiler-nix-name: {
-                inherit compiler-nix-name;
-              });
-              # we also want cross compilation to windows.
-              crossPlatforms = p: [p.mingwW64];
-            }
-          );
+        flake = cabalProject.flake {};
       in
         lib.recursiveUpdate flake rec {
           project = cabalProject;