diff --git a/flake.nix b/flake.nix
index 31d1c54..86d2dbd 100644
--- a/flake.nix
+++ b/flake.nix
@@ -38,7 +38,7 @@
 						shellcheck
 						(xonsh.overridePythonAttrs (old: rec { python3 = basicPython; propagatedBuildInputs = old.propagatedBuildInputs ++ [ basicPython.pkgs.pyyaml ];}))
 					];
-					extraCommands = [
+					extraCommands = builtins.concatStringsSep "\n" [
 						"mkdir -p /tmp"
 						"chmod -R 777 /tmp"
 					];