diff --git a/test.nix b/test.nix
index 6f7e0fde9e47f1a7d1b6aa444977931b659d91e2..cb279c99b4017cdd77627b8f52cba923cd76bc41 100644
--- a/test.nix
+++ b/test.nix
@@ -1,11 +1,14 @@
 { pkgs ? import <nixpkgs> {},
-  testName ? "base"
+  testName ? "base",
+  nrm-override ? null,
+  containers-override ? null,
+  libnrm-override ? null
 }:
 let
   testEnv = spec: (import spec.argotest.src {
-        nrm-src=spec.nrm.src;
-        libnrm-src=spec.libnrm.src;
-        containers-src=spec.containers.src;
+        nrm-src        = if (isNull nrm-override)        then spec.nrm.src        else nrm-override;
+        libnrm-src     = if (isNull libnrm-override)     then spec.libnrm.src     else libnrm-override;
+        containers-src = if (isNull containers-override) then spec.containers.src else containers-override;
       }).test ;
   allTests = import ./tests/default.nix {};
 in testEnv allTests."${testName}"