diff --git a/nix/default.nix b/nix/default.nix
index c357f1f..58b34eb 100644
--- a/nix/default.nix
+++ b/nix/default.nix
@@ -4,6 +4,7 @@
   ocamlPackages,
   version,
   debug ? false,
+  doCheck ? false,
   ...
 }:
 ocamlPackages.buildDunePackage {
@@ -19,12 +20,19 @@ ocamlPackages.buildDunePackage {
     if debug
     then ''
       runHook preBuild
-      dune build --profile debug -p culr ''${enableParallelBuilding:+-j $NIX_BUILD_CORES}
+      dune build -p culr --profile debug ''${enableParallelBuilding:+-j $NIX_BUILD_CORES}
       runHook postBuild
     ''
     else ''
       runHook preBuild
-      dune build --profile release -p culr ''${enableParallelBuilding:+-j $NIX_BUILD_CORES}
+      dune build -p culr --profile release  ''${enableParallelBuilding:+-j $NIX_BUILD_CORES}
       runHook postBuild
     '';
+
+  checkPhase = ''
+    dune runtest
+  '';
+  inherit doCheck;
+
+  meta.mainProgram = "culr";
 }
diff --git a/nix/test.nix b/nix/test.nix
index 9efa93a..6a615b3 100644
--- a/nix/test.nix
+++ b/nix/test.nix
@@ -10,11 +10,14 @@ pkgs.stdenvNoCC.mkDerivation {
   version = "${version}";
 
   nativebuildInputs = [culr];
-
+  src = ./.;
   doCheck = true;
   checkPhase = ''
-    CULRS="(255,0,0);(0,0,255)"
-    CULR_ORDER=1,0
+    CULRS="(255,0,0);(0,0,255);#00FF00"
+    CULR_ORDER="1;0;2"
     echo "one two three four" | ${lib.getExe culr}
   '';
+  installPhase = ''
+    mkdir "$out"
+  '';
 }