diff --git a/nixos/lib/systemd-lib.nix b/nixos/lib/systemd-lib.nix
index c6c8753d5325b..f854b02f9420c 100644
--- a/nixos/lib/systemd-lib.nix
+++ b/nixos/lib/systemd-lib.nix
@@ -19,7 +19,6 @@ in rec {
     if unit.enable then
       pkgs.runCommand "unit-${mkPathSafeName name}"
         { preferLocalBuild = true;
-          allowSubstitutes = false;
           inherit (unit) text;
         }
         ''
@@ -29,9 +28,7 @@ in rec {
         ''
     else
       pkgs.runCommand "unit-${mkPathSafeName name}-disabled"
-        { preferLocalBuild = true;
-          allowSubstitutes = false;
-        }
+        { preferLocalBuild = true; }
         ''
           name=${shellEscape name}
           mkdir -p "$out/$(dirname "$name")"
@@ -131,9 +128,7 @@ in rec {
         nspawn = "nspawn";
       }).${type};
     in pkgs.runCommand "${type}-units"
-      { preferLocalBuild = true;
-        allowSubstitutes = false;
-      } ''
+      { preferLocalBuild = true; } ''
       mkdir -p $out
 
       # Copy the upstream systemd units we're interested in.
diff --git a/nixos/modules/i18n/input-method/default.nix b/nixos/modules/i18n/input-method/default.nix
index 5f803b4f2ee79..ccdfd6caa6826 100644
--- a/nixos/modules/i18n/input-method/default.nix
+++ b/nixos/modules/i18n/input-method/default.nix
@@ -6,7 +6,6 @@ let
 
   gtk2_cache = pkgs.runCommand "gtk2-immodule.cache"
     { preferLocalBuild = true;
-      allowSubstitutes = false;
       buildInputs = [ pkgs.gtk2 cfg.package ];
     }
     ''
@@ -16,7 +15,6 @@ let
 
   gtk3_cache = pkgs.runCommand "gtk3-immodule.cache"
     { preferLocalBuild = true;
-      allowSubstitutes = false;
       buildInputs = [ pkgs.gtk3 cfg.package ];
     }
     ''
diff --git a/nixos/modules/programs/fish.nix b/nixos/modules/programs/fish.nix
index 160adc0cad6d3..998ce1af5cf84 100644
--- a/nixos/modules/programs/fish.nix
+++ b/nixos/modules/programs/fish.nix
@@ -256,7 +256,6 @@ in
               cp * $out/
             '';
             preferLocalBuild = true;
-            allowSubstitutes = false;
           };
           generateCompletions = package: pkgs.runCommand
             "${package.name}_fish-completions"
@@ -264,7 +263,6 @@ in
               {
                 inherit package;
                 preferLocalBuild = true;
-                allowSubstitutes = false;
               }
               // optionalAttrs (package ? meta.priority) { meta.priority = package.meta.priority; }
             )
diff --git a/nixos/modules/services/hardware/udev.nix b/nixos/modules/services/hardware/udev.nix
index d95261332419d..d7a9c3ca36e0d 100644
--- a/nixos/modules/services/hardware/udev.nix
+++ b/nixos/modules/services/hardware/udev.nix
@@ -54,7 +54,6 @@ let
   # Perform substitutions in all udev rules files.
   udevRulesFor = { name, udevPackages, udevPath, udev, systemd, binPackages, initrdBin ? null }: pkgs.runCommand name
     { preferLocalBuild = true;
-      allowSubstitutes = false;
       packages = unique (map toString udevPackages);
     }
     ''
@@ -156,7 +155,6 @@ let
 
   hwdbBin = pkgs.runCommand "hwdb.bin"
     { preferLocalBuild = true;
-      allowSubstitutes = false;
       packages = unique (map toString ([udev] ++ cfg.packages));
     }
     ''
diff --git a/nixos/modules/services/x11/display-managers/default.nix b/nixos/modules/services/x11/display-managers/default.nix
index 995ecd231c437..2739f8f097e9b 100644
--- a/nixos/modules/services/x11/display-managers/default.nix
+++ b/nixos/modules/services/x11/display-managers/default.nix
@@ -111,7 +111,6 @@ let
   installedSessions = pkgs.runCommand "desktops"
     { # trivial derivation
       preferLocalBuild = true;
-      allowSubstitutes = false;
     }
     ''
       mkdir -p "$out/share/"{xsessions,wayland-sessions}
diff --git a/nixos/modules/system/activation/top-level.nix b/nixos/modules/system/activation/top-level.nix
index 240e209591752..1d140ffae582d 100644
--- a/nixos/modules/system/activation/top-level.nix
+++ b/nixos/modules/system/activation/top-level.nix
@@ -96,7 +96,6 @@ let
   baseSystem = pkgs.stdenvNoCC.mkDerivation ({
     name = "nixos-system-${config.system.name}-${config.system.nixos.label}";
     preferLocalBuild = true;
-    allowSubstitutes = false;
     buildCommand = systemBuilder;
 
     inherit (pkgs) coreutils;