diff --git a/morph/grid/local/grid.nix b/morph/grid/local/grid.nix
index 5d05da12286f8a54d8b6df41e4d3bf35df7bff2a..bca902f20440e60e7d71162f273dd65d67317545 100644
--- a/morph/grid/local/grid.nix
+++ b/morph/grid/local/grid.nix
@@ -71,7 +71,6 @@ let
 in {
   network = {
     description = "PrivateStorage.io LocalDev Grid";
-    pkgs = import ../../../stable2105.nix { };
   };
   inherit payments monitoring storage1 storage2;
 }
diff --git a/morph/grid/production/grid.nix b/morph/grid/production/grid.nix
index fe66dc39e92a3403876d5dc3458b190832d035c2..1aa605615dc26c9394f4f7143f5f50975107cffe 100644
--- a/morph/grid/production/grid.nix
+++ b/morph/grid/production/grid.nix
@@ -108,7 +108,6 @@ let
 in {
   network = {
     description = "PrivateStorage.io Production Grid";
-    pkgs = import ../../../stable2105.nix { };
   };
   inherit payments;
   inherit monitoring;
diff --git a/morph/grid/testing/grid.nix b/morph/grid/testing/grid.nix
index 07adee2c438bb5c0b20dd20ea1e4005d3234713a..996b1fba0bd2c12c22b00f549aa26c8b8472653d 100644
--- a/morph/grid/testing/grid.nix
+++ b/morph/grid/testing/grid.nix
@@ -60,7 +60,6 @@ let
 in {
   network = {
     description = "PrivateStorage.io Testing Grid";
-    pkgs = import ../../../stable2105.nix { };
   };
   inherit payments monitoring storage001;
 }
diff --git a/nixos/modules/issuer.nix b/nixos/modules/issuer.nix
index f28f8f6c94242241cc368d1524acf3ff1d3c86b6..bdf8addc4521398c7063ad96ed6c8258d93aebea 100644
--- a/nixos/modules/issuer.nix
+++ b/nixos/modules/issuer.nix
@@ -3,7 +3,7 @@
 { lib, pkgs, config, ... }: let
   cfg = config.services.private-storage-issuer;
   # Our own nixpkgs fork:
-  ourpkgs = import (builtins.fetchTarball (builtins.fromJSON (builtins.readFile ../../nixpkgs.json))) { };
+  ourpkgs = import ../../pspkgs.nix {};
 in {
   imports = [
     # Give it a good SSH configuration.
diff --git a/nixos/modules/private-storage.nix b/nixos/modules/private-storage.nix
index 4f6561a0e00038aeb5abf80912689559689528c4..17ef5a0971197d2e03d35e5715019f933d93703b 100644
--- a/nixos/modules/private-storage.nix
+++ b/nixos/modules/private-storage.nix
@@ -9,7 +9,7 @@ let
   tahoe-base = "/var/db/tahoe-lafs";
 
   # Our own nixpkgs fork:
-  ourpkgs = import (builtins.fetchTarball (builtins.fromJSON (builtins.readFile ../../nixpkgs.json))) { };
+  ourpkgs = import ../../pspkgs.nix {};
 
   # The full path to the directory where the storage server will write
   # incident reports.
diff --git a/nixpkgs.json b/nixpkgs-ps.json
similarity index 88%
rename from nixpkgs.json
rename to nixpkgs-ps.json
index e8a900d44fc2a08a09c4e1f6447da3a4a6a52fd1..c5b01313cacdfc86f06e3baa82fb1d605c35da56 100644
--- a/nixpkgs.json
+++ b/nixpkgs-ps.json
@@ -1,4 +1,4 @@
-{ "name": "nixpkgs"
+{ "name": "nixpkgs-ps"
 , "url": "https://github.com/PrivateStorageio/nixpkgs/archive/788cc5806d46b89013ddd59db589b748bc20435e.tar.gz"
 , "sha256": "1mjznn4i4524gl5aiapjpy2jzpac1fzp7jvnkamrh9090ndalhar"
 }
diff --git a/pspkgs.nix b/pspkgs.nix
new file mode 100644
index 0000000000000000000000000000000000000000..d98a53843052fda824f4ed7e34db50524df36ce2
--- /dev/null
+++ b/pspkgs.nix
@@ -0,0 +1 @@
+import (builtins.fetchTarball (builtins.fromJSON (builtins.readFile ./nixpkgs-ps.json)))
diff --git a/shell.nix b/shell.nix
index df272a12e2241c704a4c08c6d60d47bb138bcae5..7bd00916fe4bef5c13a78dcf3c9a4ae51f359165 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,8 +1,8 @@
 let
-  nixpkgs = import (builtins.fetchTarball (builtins.fromJSON (builtins.readFile ./nixpkgs.json))) { };
+  # ourpkgs = import ./pspkgs.nix { };
   stable2105 = import ./stable2105.nix { };
 in
-{ pkgs ? nixpkgs }:
+{ pkgs ? stable2105 }:
 pkgs.mkShell {
   NIX_PATH = "nixpkgs=${pkgs.path}";
   buildInputs = [