diff --git a/system/common/nix.nix b/system/common/nix.nix
index 784fcb9..c78c222 100644
--- a/system/common/nix.nix
+++ b/system/common/nix.nix
@@ -32,7 +32,15 @@ in
             id = "nixpkgs";
             type = "indirect";
           };
-          flake = inputs.nixpkgs;
+
+          # used instead of `flake` option so produced flake.lock files are
+          # portable
+          to = {
+            type = "github";
+            owner = "NixOS";
+            repo = "nixpkgs";
+            rev = "${inputs.nixpkgs.rev}";
+          };
         };
       };