diff --git a/flake.lock b/flake.lock
index 73f0a02..61e64a7 100644
--- a/flake.lock
+++ b/flake.lock
@@ -177,22 +177,6 @@
       }
     },
     "flake-compat_4": {
-      "flake": false,
-      "locked": {
-        "lastModified": 1673956053,
-        "narHash": "sha256-4gtG9iQuiKITOjNQQeQIpoIB6b16fm+504Ch3sNKLd8=",
-        "owner": "edolstra",
-        "repo": "flake-compat",
-        "rev": "35bb57c0c8d8b62bbfd284272c928ceb64ddbde9",
-        "type": "github"
-      },
-      "original": {
-        "owner": "edolstra",
-        "repo": "flake-compat",
-        "type": "github"
-      }
-    },
-    "flake-compat_5": {
       "locked": {
         "lastModified": 1688025799,
         "narHash": "sha256-ktpB4dRtnksm9F5WawoIkEneh1nrEvuxb5lJFt1iOyw=",
@@ -472,22 +456,6 @@
         "type": "github"
       }
     },
-    "lowdown-src": {
-      "flake": false,
-      "locked": {
-        "lastModified": 1633514407,
-        "narHash": "sha256-Dw32tiMjdK9t3ETl5fzGrutQTzh2rufgZV4A/BbxuD4=",
-        "owner": "kristapsdz",
-        "repo": "lowdown",
-        "rev": "d2c2b44ff6c27b936ec27358a2653caaef8f73b8",
-        "type": "github"
-      },
-      "original": {
-        "owner": "kristapsdz",
-        "repo": "lowdown",
-        "type": "github"
-      }
-    },
     "nix-index-database": {
       "inputs": {
         "nixpkgs": [
@@ -508,28 +476,6 @@
         "type": "github"
       }
     },
-    "nix-rfc-92": {
-      "inputs": {
-        "flake-compat": "flake-compat_4",
-        "lowdown-src": "lowdown-src",
-        "nixpkgs": "nixpkgs_4",
-        "nixpkgs-regression": "nixpkgs-regression"
-      },
-      "locked": {
-        "lastModified": 1692633754,
-        "narHash": "sha256-qktpqyNrfjmsCWi6G2aesMJEUAfBymNlzHWJXU0LOI8=",
-        "owner": "obsidiansystems",
-        "repo": "nix",
-        "rev": "b65b45cca5bdd56f80bf089e1ee8523afa81a2e9",
-        "type": "github"
-      },
-      "original": {
-        "owner": "obsidiansystems",
-        "ref": "dynamic-drvs",
-        "repo": "nix",
-        "type": "github"
-      }
-    },
     "nixd": {
       "inputs": {
         "flake-parts": "flake-parts_2",
@@ -553,8 +499,8 @@
     },
     "nixos-apple-silicon": {
       "inputs": {
-        "flake-compat": "flake-compat_5",
-        "nixpkgs": "nixpkgs_5",
+        "flake-compat": "flake-compat_4",
+        "nixpkgs": "nixpkgs_4",
         "rust-overlay": "rust-overlay_3"
       },
       "locked": {
@@ -605,22 +551,6 @@
         "type": "github"
       }
     },
-    "nixpkgs-regression": {
-      "locked": {
-        "lastModified": 1643052045,
-        "narHash": "sha256-uGJ0VXIhWKGXxkeNnq4TvV3CIOkUJ3PAoLZ3HMzNVMw=",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "215d4d0fd80ca5163643b03a33fde804a29cc1e2",
-        "type": "github"
-      },
-      "original": {
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "215d4d0fd80ca5163643b03a33fde804a29cc1e2",
-        "type": "github"
-      }
-    },
     "nixpkgs-stable": {
       "locked": {
         "lastModified": 1678872516,
@@ -670,22 +600,6 @@
       }
     },
     "nixpkgs_4": {
-      "locked": {
-        "lastModified": 1670461440,
-        "narHash": "sha256-jy1LB8HOMKGJEGXgzFRLDU1CBGL0/LlkolgnqIsF0D8=",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "04a75b2eecc0acf6239acf9dd04485ff8d14f425",
-        "type": "github"
-      },
-      "original": {
-        "owner": "NixOS",
-        "ref": "nixos-22.11-small",
-        "repo": "nixpkgs",
-        "type": "github"
-      }
-    },
-    "nixpkgs_5": {
       "locked": {
         "lastModified": 1690031011,
         "narHash": "sha256-kzK0P4Smt7CL53YCdZCBbt9uBFFhE0iNvCki20etAf4=",
@@ -701,7 +615,7 @@
         "type": "github"
       }
     },
-    "nixpkgs_6": {
+    "nixpkgs_5": {
       "locked": {
         "lastModified": 1692794066,
         "narHash": "sha256-H0aG8r16dj0x/Wz6wQhQxc9V7AsObOiHPaKxQgH6Y08=",
@@ -760,10 +674,9 @@
         "lanzaboote": "lanzaboote",
         "linkal": "linkal",
         "nix-index-database": "nix-index-database",
-        "nix-rfc-92": "nix-rfc-92",
         "nixd": "nixd",
         "nixos-apple-silicon": "nixos-apple-silicon",
-        "nixpkgs": "nixpkgs_6",
+        "nixpkgs": "nixpkgs_5",
         "simple-nixos-mailserver": "simple-nixos-mailserver",
         "sops-nix": "sops-nix",
         "unstable": "unstable"
diff --git a/flake.nix b/flake.nix
index a608ee9..fd02c0a 100644
--- a/flake.nix
+++ b/flake.nix
@@ -63,8 +63,6 @@
       inputs.nixpkgs.follows = "nixpkgs";
     };
 
-    nix-rfc-92.url = "github:obsidiansystems/nix/dynamic-drvs";
-
     lanzaboote = {
       url = "github:nix-community/lanzaboote/v0.3.0";
       inputs.nixpkgs.follows = "nixpkgs";