diff --git a/nixos/modules/installer/cd-dvd/installation-cd-graphical-base.nix b/nixos/modules/installer/cd-dvd/installation-cd-graphical-base.nix
index 4a00c52916f69..fff0407cf576f 100644
--- a/nixos/modules/installer/cd-dvd/installation-cd-graphical-base.nix
+++ b/nixos/modules/installer/cd-dvd/installation-cd-graphical-base.nix
@@ -66,4 +66,13 @@ with lib;
     glxinfo
   ];
 
+  nixpkgs.overlays = [
+    (self: super: {
+      mbrola-voices = super.mbrola-voices.override {
+        # only ship with one voice per language
+        languages = [ "*1" ];
+      };
+    })
+  ];
+
 }
diff --git a/pkgs/applications/audio/mbrola/default.nix b/pkgs/applications/audio/mbrola/default.nix
index 6cc20269dcf31..888ae82cdbab5 100644
--- a/pkgs/applications/audio/mbrola/default.nix
+++ b/pkgs/applications/audio/mbrola/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, lib, fetchFromGitHub, runCommandLocal }:
+{ stdenv, lib, fetchFromGitHub, runCommandLocal, mbrola-voices }:
 
 let
   pname = "mbrola";
@@ -12,20 +12,6 @@ let
     homepage = "https://github.com/numediart/MBROLA";
   };
 
-  # Very big (0.65 G) so kept as a fixed-output derivation to limit "duplicates".
-  voices = fetchFromGitHub {
-    owner = "numediart";
-    repo = "MBROLA-voices";
-    rev = "fe05a0ccef6a941207fd6aaad0b31294a1f93a51";  # using latest commit
-    sha256 = "1w0y2xjp9rndwdjagp2wxh656mdm3d6w9cs411g27rjyfy1205a0";
-
-    name = "${pname}-voices-${version}";
-    meta = meta // {
-      description = "Speech synthesizer based on the concatenation of diphones (voice files)";
-      homepage = "https://github.com/numediart/MBROLA-voices";
-    };
-  };
-
   bin = stdenv.mkDerivation {
     pname = "${pname}-bin";
     inherit version;
@@ -60,7 +46,7 @@ in
     }
     ''
       mkdir -p "$out/share/mbrola"
-      ln -s '${voices}/data' "$out/share/mbrola/voices"
+      ln -s '${mbrola-voices}/data' "$out/share/mbrola/voices"
       ln -s '${bin}/bin' "$out/"
     ''
 
diff --git a/pkgs/applications/audio/mbrola/voices.nix b/pkgs/applications/audio/mbrola/voices.nix
new file mode 100644
index 0000000000000..79d0910252f4d
--- /dev/null
+++ b/pkgs/applications/audio/mbrola/voices.nix
@@ -0,0 +1,52 @@
+{
+  lib,
+  stdenv,
+  fetchFromGitHub,
+  unstableGitUpdater,
+  mbrola,
+  languages ? [ ],
+}:
+
+let
+  pname = "mbrola-voices";
+  version = "3.3"; # FIXME: revert this line on staging*
+
+  src = fetchFromGitHub {
+    owner = "numediart";
+    repo = "MBROLA-voices";
+    rev = "fe05a0ccef6a941207fd6aaad0b31294a1f93a51";
+    hash = "sha256-QBUggnde5iNeCESzxE0btVVTDOxc3Kdk483mdGUXHvA=";
+    name = "${pname}-${version}";
+  };
+
+  meta = {
+    description = "Speech synthesizer based on the concatenation of diphones (voice files)";
+    homepage = "https://github.com/numediart/MBROLA-voices";
+    license = mbrola.meta.license;
+  };
+in
+
+if (languages == [ ]) then
+  src // { inherit meta; }
+else
+  stdenv.mkDerivation {
+    inherit pname version src;
+
+    postPatch = ''
+      shopt -s extglob
+      pushd data
+      rm -rfv !(${lib.concatStringsSep "|" languages})
+      popd
+    '';
+
+    installPhase = ''
+      runHook preInstall
+
+      mkdir $out
+      cp -R data $out/
+
+      runHook postInstall
+    '';
+
+    inherit meta;
+  }
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 8338627524846..380ea5871c53b 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -32208,6 +32208,8 @@ with pkgs;
 
   mbrola = callPackage ../applications/audio/mbrola { };
 
+  mbrola-voices = callPackage ../applications/audio/mbrola/voices.nix { };
+
   mcpp = callPackage ../development/compilers/mcpp { };
 
   mda_lv2 = callPackage ../applications/audio/mda-lv2 { };