diff --git a/flake.lock b/flake.lock
index b41b843a..75023b95 100644
--- a/flake.lock
+++ b/flake.lock
@@ -23,32 +23,32 @@
         "nixpkgs-regression": "nixpkgs-regression"
       },
       "locked": {
-        "lastModified": 1661606874,
-        "narHash": "sha256-9+rpYzI+SmxJn+EbYxjGv68Ucp22bdFUSy/4LkHkkDQ=",
-        "owner": "NixOS",
+        "lastModified": 1675514340,
+        "narHash": "sha256-JjnneK+TkhkxFoh6EEVKAzEBdxz0iucZsJ6+PWTTReQ=",
+        "owner": "nixos",
         "repo": "nix",
-        "rev": "11e45768b34fdafdcf019ddbd337afa16127ff0f",
+        "rev": "9157f94e775936798c1f8783eab929e77904e5ed",
         "type": "github"
       },
       "original": {
-        "owner": "NixOS",
-        "ref": "2.11.0",
+        "owner": "nixos",
+        "ref": "2.13-maintenance",
         "repo": "nix",
         "type": "github"
       }
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1657693803,
-        "narHash": "sha256-G++2CJ9u0E7NNTAi9n5G8TdDmGJXcIjkJ3NF8cetQB8=",
+        "lastModified": 1670461440,
+        "narHash": "sha256-jy1LB8HOMKGJEGXgzFRLDU1CBGL0/LlkolgnqIsF0D8=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "365e1b3a859281cf11b94f87231adeabbdd878a2",
+        "rev": "04a75b2eecc0acf6239acf9dd04485ff8d14f425",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
-        "ref": "nixos-22.05-small",
+        "ref": "nixos-22.11-small",
         "repo": "nixpkgs",
         "type": "github"
       }
diff --git a/flake.nix b/flake.nix
index cd9f094d..208d9017 100644
--- a/flake.nix
+++ b/flake.nix
@@ -2,7 +2,7 @@
   description = "A Nix-based continuous build system";
 
   inputs.nixpkgs.follows = "nix/nixpkgs";
-  inputs.nix.url = "github:NixOS/nix/2.11.0";
+  inputs.nix.url = "github:nixos/nix/2.13-maintenance";
 
   outputs = { self, nixpkgs, nix }:
     let
diff --git a/src/hydra-eval-jobs/hydra-eval-jobs.cc b/src/hydra-eval-jobs/hydra-eval-jobs.cc
index 18d39620..de7ae7ba 100644
--- a/src/hydra-eval-jobs/hydra-eval-jobs.cc
+++ b/src/hydra-eval-jobs/hydra-eval-jobs.cc
@@ -129,7 +129,7 @@ static void worker(
             LockFlags {
                 .updateLockFile = false,
                 .useRegistries = false,
-                .allowMutable = false,
+                .allowUnlocked = false,
             });
 
         callFlake(state, lockedFlake, *vFlake);