diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 8c3f53472cb..ef130f70a25 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -9,7 +9,7 @@
 
 
 { # The system (e.g., `i686-linux') for which to build the packages.
-  system ? __currentSystem
+  system ? builtins.currentSystem
 
   # Usually, the system type uniquely determines the stdenv and thus
   # how to build the packages.  But on some platforms we have