diff --git a/default.nix b/default.nix
new file mode 100644
index 00000000..3c08d637
--- /dev/null
+++ b/default.nix
@@ -0,0 +1,10 @@
+(import
+  (
+    fetchTarball {
+      url = "https://github.com/edolstra/flake-compat/archive/99f1c2157fba4bfe6211a321fd0ee43199025dbf.tar.gz";
+      sha256 = "sha256:0x2jn3vrawwv9xp15674wjz9pixwjyj3j771izayl962zziivbx2";
+    }
+  )
+  {
+    src = ./.;
+  }).defaultNix.packages.x86_64-linux
diff --git a/flake.lock b/flake.lock
index d85c8c0f..5c29be16 100644
--- a/flake.lock
+++ b/flake.lock
@@ -52,11 +52,11 @@
     },
     "master": {
       "locked": {
-        "lastModified": 1607981906,
-        "narHash": "sha256-tFuNBkK0F5km1Lq5ulLgLVm3BvOvI7t4k4Y7xTIo3QE=",
+        "lastModified": 1610960440,
+        "narHash": "sha256-0ZDzGoFhROKZwcW2Sa2CXiwYL6br09JORgEHr58w/Ew=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "dd95aa337e23a8a48fe82f0f7b1cced8bc03e379",
+        "rev": "3bdf95ceb5660273a01ed2e5be2676487f7e820e",
         "type": "github"
       },
       "original": {
@@ -67,11 +67,11 @@
     },
     "nixos": {
       "locked": {
-        "lastModified": 1607967859,
-        "narHash": "sha256-biRVmLlWfxIvB2O+mkFbObb4MmCzbYvpy5Rap4g9Mig=",
+        "lastModified": 1610885893,
+        "narHash": "sha256-VAETd1jhnWUJmq0b8Dbi9mo4qvS+AYC3d9tmVfnf2zQ=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "7362dab2c9bd21eeef831f32608161584b388ef4",
+        "rev": "3888fe83e1c7b5331d032177b039e91f83bf34e1",
         "type": "github"
       },
       "original": {
diff --git a/flake.nix b/flake.nix
index 3b4120a5..73d04eab 100644
--- a/flake.nix
+++ b/flake.nix
@@ -27,26 +27,29 @@
       externOverlays = [ nur.overlay devshell.overlay ];
       externModules = [ home.nixosModules.home-manager ];
 
+      pkgs' = unstable:
+        let
+          override = import ./pkgs/override.nix;
+          overlays = (attrValues self.overlays)
+            ++ externOverlays
+            ++ [ self.overlay (override unstable) ];
+        in
+        pkgImport nixos overlays;
+
+      unstable' = pkgImport master [ ];
+
       osSystem = "x86_64-linux";
 
       outputs =
         let
           system = osSystem;
-          pkgset =
-            let
-              overlays =
-                (attrValues self.overlays)
-                ++ externOverlays
-                ++ [ self.overlay ];
-            in
-            genPkgset {
-              inherit master nixos overlays system;
-            };
+          unstablePkgs = unstable' system;
+          osPkgs = pkgs' unstablePkgs system;
         in
         {
           nixosConfigurations =
             import ./hosts (recursiveUpdate inputs {
-              inherit lib pkgset utils externModules system;
+              inherit lib osPkgs unstablePkgs utils externModules system;
             });
 
           overlay = import ./pkgs;
@@ -66,11 +69,8 @@
       (eachDefaultSystem
         (system:
           let
-            pkgs = pkgImport {
-              inherit system;
-              pkgs = nixos;
-              overlays = [ devshell.overlay ];
-            };
+            unstablePkgs = unstable' system;
+            pkgs = pkgs' unstablePkgs system;
 
             packages = flattenTreeSystem system
               (genPackages {
diff --git a/hosts/default.nix b/hosts/default.nix
index 64af30cf..af2a363c 100644
--- a/hosts/default.nix
+++ b/hosts/default.nix
@@ -3,9 +3,10 @@
 , nixos
 , master
 , nixos-hardware
-, pkgset
+, osPkgs
 , self
 , system
+, unstablePkgs
 , utils
 , externModules
 , ...
@@ -13,7 +14,6 @@
 let
   inherit (utils) recImport;
   inherit (builtins) attrValues removeAttrs;
-  inherit (pkgset) osPkgs unstablePkgs;
 
   unstableModules = [ ];
   addToDisabledModules = [ ];
@@ -67,14 +67,6 @@ let
             system.configurationRevision = lib.mkIf (self ? rev) self.rev;
           };
 
-          overrides = {
-            nixpkgs.overlays =
-              let
-                override = import ../pkgs/override.nix unstablePkgs;
-              in
-              [ override ];
-          };
-
           local = import "${toString ./.}/${hostName}.nix";
 
           # Everything in `./modules/list.nix`.
@@ -86,7 +78,6 @@ let
           core
           global
           local
-          overrides
           modOverrides
         ] ++ externModules;
 
diff --git a/lib/utils.nix b/lib/utils.nix
index 7980636f..8dc6d9e6 100644
--- a/lib/utils.nix
+++ b/lib/utils.nix
@@ -1,8 +1,8 @@
 { lib, ... }:
 let
-  inherit (builtins) attrNames isAttrs readDir listToAttrs;
+  inherit (builtins) attrNames attrValues isAttrs readDir listToAttrs mapAttrs;
 
-  inherit (lib) filterAttrs hasSuffix mapAttrs' nameValuePair removeSuffix
+  inherit (lib) fold filterAttrs hasSuffix mapAttrs' nameValuePair removeSuffix
     recursiveUpdate genAttrs;
 
   # mapFilterAttrs ::
@@ -14,8 +14,8 @@ let
   # Generate an attribute set by mapping a function over a list of values.
   genAttrs' = values: f: listToAttrs (map f values);
 
-  pkgImport = { pkgs, system, overlays }:
-    import pkgs {
+  pkgImport = nixpkgs: overlays: system:
+    import nixpkgs {
       inherit system overlays;
       config = { allowUnfree = true; };
     };
@@ -33,20 +33,6 @@ in
 {
   inherit mapFilterAttrs genAttrs' pkgImport pathsToImportedAttrs;
 
-  genPkgset = { master, nixos, overlays, system }:
-    {
-      osPkgs = pkgImport {
-        inherit system overlays;
-        pkgs = nixos;
-      };
-
-      unstablePkgs = pkgImport {
-        inherit system;
-        overlays = [];
-        pkgs = master;
-      };
-    };
-
   overlayPaths =
     let
       overlayDir = ../overlays;
@@ -86,12 +72,19 @@ in
   genPackages = { self, pkgs }:
     let
       inherit (self) overlay overlays;
-      packages = overlay pkgs pkgs;
-      overlayPkgs =
-        genAttrs
-          (attrNames overlays)
-          (name: (overlays."${name}" pkgs pkgs)."${name}");
+      packagesNames = attrNames (overlay null null)
+        ++ attrNames (fold
+        (attr: sum: recursiveUpdate sum attr)
+        { }
+        (attrValues
+          (mapAttrs (_: v: v null null) overlays)
+        )
+      );
     in
-    recursiveUpdate packages overlayPkgs;
-
+    fold
+      (key: sum: recursiveUpdate sum {
+        ${key} = pkgs.${key};
+      })
+      { }
+      packagesNames;
 }
diff --git a/pkgs/default.nix b/pkgs/default.nix
index e1a94dd0..fd75896f 100644
--- a/pkgs/default.nix
+++ b/pkgs/default.nix
@@ -8,5 +8,4 @@ final: prev: {
   libinih = prev.callPackage ./development/libraries/libinih { };
   steamcompmgr =
     prev.callPackage ./applications/window-managers/steamcompmgr { };
-  miningcore = prev.callPackage ./applications/blockchains/miningcore { };
 }