diff --git a/pkgs/overlays/unstable.nix b/pkgs/overlays/unstable.nix
index 2a20c30..9aa8f2c 100644
--- a/pkgs/overlays/unstable.nix
+++ b/pkgs/overlays/unstable.nix
@@ -2,21 +2,12 @@ self: super:
 
 let
   nixos = self.config.nixos or true;
-  unstableRevision = self.config.unstableRevision or null;
-  unstableRevisionHash = self.config.unstableRevisionHash or null;
   useUnstable = self.config.useUnstable or true;
 
-  unstablePkgsExprs = if !builtins.isNull unstableRevision
-    then if !builtins.isNull unstableRevisionHash
-      then builtins.fetchTarball {
-        url = "https://github.com/NixOS/nixpkgs/archive/${unstableRevision}.tar.gz";
-        sha256 = unstableRevisionHash;
-      }
-      else builtins.fetchTarball "https://github.com/NixOS/nixpkgs/archive/${unstableRevision}.tar.gz"
-    else if nixos
-      then builtins.fetchTarball "https://channels.nixos.org/nixos-unstable/nixexprs.tar.xz"
-      else builtins.fetchTarball "https://channels.nixos.org/nixpkgs-unstable/nixexprs.tar.xz";
-
+  unstablePkgsExprs = if nixos
+    then builtins.fetchTarball "https://channels.nixos.org/nixos-unstable/nixexprs.tar.xz"
+    else builtins.fetchTarball "https://channels.nixos.org/nixpkgs-unstable/nixexprs.tar.xz";
+  
   # Compiled nixpkgs expression eg expressions from a nix channel
   nixpkgsVersion = builtins.concatStringsSep "." [
     (builtins.readFile "${unstablePkgsExprs}/.version")
@@ -25,10 +16,10 @@ let
 
   nixpkgsRevision = (builtins.readFile "${unstablePkgsExprs}/.git-revision");
   unstablePkgsForNixpkgs = nixpkgs: import unstablePkgsExprs {
-    # localSystem -> pkgs.stdenv.buildPlatform
-    localSystem = nixpkgs.stdenv.buildPlatform;
-    # crossSystem -> pkgs.stdenv.hostPlatform or pkgs.stdenv.targetPlatform ??
-    crossSystem = nixpkgs.stdenv.hostPlatform;
+    # localSystem -> pkgs.stdenv.hostPlatform or pkgs.stdenv.hostPlatform ???
+    localSystem = nixpkgs.stdenv.hostPlatform;
+    # crossSystem -> nixpkgs.stdenv.targetPlatform
+    crossSystem = nixpkgs.stdenv.targetPlatform;
     # config -> pkgs.config
     config = nixpkgs.config;
     # overlays -> partial of pkgs.overlays