diff --git a/default.nix b/default.nix
index 0a0f3316..531e8e87 100644
--- a/default.nix
+++ b/default.nix
@@ -1,4 +1,14 @@
-{sources ? import ./npins}: {
+{sources ? import ./npins}: let
+  # Catch where currentSystem is evaluated
+  fakeImport = builtins.scopedImport {
+    builtins =
+      builtins
+      // {
+        currentSystem = throw "`currentSystem' is disabled";
+      };
+    import = fakeImport;
+  };
+in {
   lib = import (sources.nixpkgs + "/lib");
 
   nixosConfigurations = builtins.mapAttrs (_: import (sources.nixpkgs + "/nixos/lib/eval-config.nix")) {