diff --git a/default.nix b/default.nix
index 21608bb19..aa23072f4 100644
--- a/default.nix
+++ b/default.nix
@@ -1,6 +1,6 @@
 argumentPackages@{ ... }:
 
 let
-  defaultPackages = (import <nixpkgs> {}).haskellPackages;
+  defaultPackages = (import ./stackage.nix {});
   haskellPackages = defaultPackages // argumentPackages;
 in import ./uniworx.nix { inherit (haskellPackages) callPackage; }
diff --git a/nixpkgs.nix b/nixpkgs.nix
new file mode 100644
index 000000000..8fe34d083
--- /dev/null
+++ b/nixpkgs.nix
@@ -0,0 +1,9 @@
+{ nixpkgs ? import <nixpkgs>
+}:
+
+import ((nixpkgs {}).fetchFromGitHub {
+  owner = "NixOS";
+  repo = "nixpkgs";
+  rev = "19.03";
+  sha256 = "0qixmc228vay4jywf14cg72m1g07ffsl75xg5qrdj70hw9xbd6sg";
+})
diff --git a/shell.nix b/shell.nix
index b942f99b9..d65bb65a3 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,4 +1,4 @@
-{ nixpkgs ? import <nixpkgs> }:
+{ nixpkgs ? import ./nixpkgs.nix {} }:
 
 let
   inherit (nixpkgs {}) pkgs;
diff --git a/stack.nix b/stack.nix
index c78220b4c..27cc60e5f 100644
--- a/stack.nix
+++ b/stack.nix
@@ -1,4 +1,4 @@
-{ ghc, nixpkgs ? import <nixpkgs> }:
+{ ghc, nixpkgs ? import ./nixpkgs.nix }:
 
 let
   haskellPackages = import ./stackage.nix { inherit nixpkgs; };
diff --git a/stackage.nix b/stackage.nix
index 4fb2c4623..e16045a40 100644
--- a/stackage.nix
+++ b/stackage.nix
@@ -1,4 +1,4 @@
-{ nixpkgs ? import <nixpkgs>
+{ nixpkgs ? import ./nixpkgs.nix {}
 , snapshot ? "lts-10.5"
 }: