diff --git a/pkgs/top-level/impure.nix b/pkgs/top-level/impure.nix
index 463de791a1a65..7f0099b254f0f 100644
--- a/pkgs/top-level/impure.nix
+++ b/pkgs/top-level/impure.nix
@@ -86,5 +86,6 @@ assert args ? system -> !(args ? localSystem);
 
 import ./. (builtins.removeAttrs args [ "system" ] // {
   inherit config overlays localSystem;
+} // (if ((localSystem.system or localSystem) == "x86_64-linux" || (localSystem.system or localSystem) == "aarch64-linux") then {
   crossSystem = { config = "aarch64-unknown-linux-gnu"; };
-})
+  } else {}) )