diff --git a/modules/services/system/dbus.nix b/modules/services/system/dbus.nix
index b01cd7bc2ff..f7fbb23d0a7 100644
--- a/modules/services/system/dbus.nix
+++ b/modules/services/system/dbus.nix
@@ -12,6 +12,7 @@ let
 
   configDir = pkgs.stdenv.mkDerivation {
     name = "dbus-conf";
+    preferLocalBuild = true;
     buildCommand = ''
       ensureDir $out
 
diff --git a/modules/system/etc/etc.nix b/modules/system/etc/etc.nix
index c84d96829f3..ec6e4e72012 100644
--- a/modules/system/etc/etc.nix
+++ b/modules/system/etc/etc.nix
@@ -30,6 +30,8 @@ let
 
     builder = ./make-etc.sh;
 
+    preferLocalBuild = true;
+
     /* !!! Use toXML. */
     sources = map (x: x.source) config.environment.etc;
     targets = map (x: x.target) config.environment.etc;