diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..df06270
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,9 @@
+build:
+
+install:
+	mkdir -p $(PREFIX)/bin $(PREFIX)/share
+	cp direnv-cache $(PREFIX)/bin
+	cp direnvrc $(PREFIX)/share
+
+check:
+	term-test -s tests
diff --git a/default.nix b/default.nix
index 639d8c8..84462b4 100644
--- a/default.nix
+++ b/default.nix
@@ -1,3 +1,13 @@
-{ pkgs ? import <nixpkgs> {} }:
-(pkgs.writers.writeBashBin "direnv-cache" ./direnv-cache).overrideAttrs
-  (o: { passthru = { direnvrc = ./direnvrc; }; })
+{ stdenv, direnv, term-test }:
+
+stdenv.mkDerivation {
+  name = "direnv-cache";
+  src = ./.;
+  propagatedBuildInputs = [ direnv ];
+  installPhase = ''
+    make install PREFIX=$out
+  '';
+  checkInputs = [ term-test ];
+  doCheck = true;
+  passthru = { direnvrc = ./direnvrc; };
+}
diff --git a/direnvrc b/direnvrc
index 11972dd..a80231a 100644
--- a/direnvrc
+++ b/direnvrc
@@ -14,4 +14,3 @@ cache() {
         echo "Environment not cached"
     fi
 }
-
diff --git a/shell.nix b/shell.nix
new file mode 100644
index 0000000..d0cf41d
--- /dev/null
+++ b/shell.nix
@@ -0,0 +1,2 @@
+{ pkgs ? import <nixpkgs> {} }:
+pkgs.callPackage ./. {}
diff --git a/tests/test_direnv_stable_behavior b/tests/test_direnv_stable_behavior
new file mode 100644
index 0000000..e5c76d5
--- /dev/null
+++ b/tests/test_direnv_stable_behavior
@@ -0,0 +1,33 @@
+# -*- mode: sh -*-
+
+function initDirenv {
+    # direnv needs a writable home:
+    run "export HOME=$(pwd)"
+    run 'eval "$(direnv hook bash)"'
+}
+
+function test_simpleEnvrcWorks {
+    initDirenv
+
+    writeFile .envrc <<EOF
+          export FOO=bar
+EOF
+    run "direnv allow"
+    assert "$(getEnv FOO)" == bar
+}
+
+function test_direnvExecRunsInCleanEnv {
+    initDirenv
+
+    run "export FOO=baz"
+
+    writeFile .envrc <<EOF
+          export FOO=bar
+EOF
+
+    run "direnv allow"
+    assert "$(getEnv FOO)" == bar
+    #captureShell 'echo $FOO'
+    #captureShell 'direnv exec /proc env | grep FOO'
+    assert "$(captureShell 'direnv exec /proc env | grep FOO')" == "FOO=baz"
+}