diff --git a/nixos/modules/profiles/installation-device.nix b/nixos/modules/profiles/installation-device.nix
index 7e5aec053df9..7e22d4b6b684 100644
--- a/nixos/modules/profiles/installation-device.nix
+++ b/nixos/modules/profiles/installation-device.nix
@@ -128,13 +128,13 @@ with lib;
     nix.settings.trusted-users = [ "nixos" ];
 
     # Install less voices for speechd to save some space
-    services.speechd.package = pkgs.speechd.override {
-      mbrola = pkgs.mbrola.override {
-        mbrola-voices = pkgs.mbrola-voices.override {
+    nixpkgs.overlays = [
+      (_: prev: {
+        mbrola-voices = prev.mbrola-voices.override {
           # only ship with one voice per language
           languages = [ "*1" ];
         };
-      };
-    };
+      })
+    ];
   };
 }