diff --git a/shell.nix b/shell.nix
index 168abb10b509c767145d4861c0d91c9375775ce5..a6addc9f2402478336235d187d8939858aa6a670 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,7 +1,13 @@
 { pkgs ? import <nixpkgs> { } }:
-(pkgs.python27.buildEnv.override {
-  extraLibs = [
-    (pkgs.callPackage ./default.nix { })
-  ];
-  ignoreCollisions = true;
-}).env
+let
+  satauthorizer = pkgs.callPackage ./default.nix { };
+in
+  (pkgs.python27.buildEnv.override {
+    extraLibs = [
+      pkgs.python27Packages.fixtures
+      pkgs.python27Packages.testtools
+      pkgs.python27Packages.hypothesis
+      satauthorizer
+    ];
+    ignoreCollisions = true;
+  }).env