diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index d7c8f554..ff02a6cf 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -45,5 +45,11 @@ Link the profile in the table in README.md and in flake.nix.
 Run ./tests/run.py to test building. The test script script will parse all the
 profiles from the README.md.
 
+You can also just specify a single profile like this:
+
+```
+ ./tests/run.py '<nixos-hardware/purism/librem/15v3>'
+```
+
 Because profiles can only be tested with the appropriate hardware, quality
 assurance is up to *you*.
diff --git a/tests/run.py b/tests/run.py
index 2f514d12..77dae8ee 100755
--- a/tests/run.py
+++ b/tests/run.py
@@ -38,6 +38,7 @@ def build_profile(
     cmd = [
         "nix",
         "build",
+        "--extra-experimental-features", "nix-command",
         "-f",
         "build-profile.nix",
         "-I",