diff --git a/ci.py b/ci.py
index e4a3d57..56512ac 100644
--- a/ci.py
+++ b/ci.py
@@ -17,7 +17,7 @@ def run(*args, **kw):
 
 
 def nix(*args):
-    return run("nix", "--extra-experimental-features", "nix-command flakes", *args, check=True, capture_output=True).stdout
+    return run("nix", "--extra-experimental-features", "nix-command flakes", "-L", *args, check=True, stdout=subprocess.PIPE).stdout
 
 
 def git(*args, check=True):