diff --git a/hosts/common/dev/nix.nix b/hosts/common/dev/nix.nix
index 4798628..58002c7 100644
--- a/hosts/common/dev/nix.nix
+++ b/hosts/common/dev/nix.nix
@@ -1,6 +1,8 @@
 {pkgs, ...}: {
+  # Make sure not to reference the extra-builtins file directly but
+  # at least via its parent folder so it can access relative files.
   nix.extraOptions = ''
     plugin-files = ${pkgs.nix-plugins}/lib/nix/plugins
-    extra-builtins-file = ${../../../nix/extra-builtins.nix}
+    extra-builtins-file = ${../../../nix}/extra-builtins.nix
   '';
 }