diff --git a/default.nix b/default.nix
index e556b69..51953df 100644
--- a/default.nix
+++ b/default.nix
@@ -1,8 +1,4 @@
-{ nixpkgsSrc ? builtins.fetchTarball {
-  url =
-    "https://github.com/NixOS/nixpkgs/archive/50a8d606f3527b88fbd9f68048944470c1b900cd.tar.gz"; # haskell-updates
-  sha256 = "07xlglmlhf3q6h8cdi3rfg4b0jk70h42kwpgwdh5b1vz149njins";
-}, pkgs ? import nixpkgsSrc { }, compiler ? null, hoogle ? true
+{ pkgs ? import ./nixpkgs.nix, compiler ? null, hoogle ? true
 , forShell ? pkgs.lib.inNixShell }:
 
 let
diff --git a/nixpkgs.nix b/nixpkgs.nix
new file mode 100644
index 0000000..c7e5cbd
--- /dev/null
+++ b/nixpkgs.nix
@@ -0,0 +1,9 @@
+let
+  nixpkgsSrc = builtins.fetchTarball {
+    url =
+      "https://github.com/NixOS/nixpkgs/archive/50a8d606f3527b88fbd9f68048944470c1b900cd.tar.gz"; # haskell-updates
+    sha256 = "07xlglmlhf3q6h8cdi3rfg4b0jk70h42kwpgwdh5b1vz149njins";
+  };
+
+in import nixpkgsSrc { }
+
diff --git a/release.nix b/release.nix
index 4aa29b4..b2a24ad 100644
--- a/release.nix
+++ b/release.nix
@@ -1,4 +1,4 @@
-{ pkgs ? import <nixpkgs> { }, compiler ? "ghc884" }:
+{ pkgs ? import ./nixpkgs.nix, compiler ? "ghc884" }:
 
 with pkgs.haskell.lib;