diff --git a/nixos/modules/system/boot/systemd.nix b/nixos/modules/system/boot/systemd.nix
index a3c83521c354..3f497566ff11 100644
--- a/nixos/modules/system/boot/systemd.nix
+++ b/nixos/modules/system/boot/systemd.nix
@@ -472,6 +472,13 @@ in
       '';
     };
 
+    systemd.generator-packages = mkOption {
+      default = [];
+      type = types.listOf types.package;
+      example = literalExample "[ pkgs.systemd-cryptsetup-generator ]";
+      description = "Packages providing systemd generators.";
+    };
+
     systemd.defaultUnit = mkOption {
       default = "multi-user.target";
       type = types.str;
@@ -628,7 +635,18 @@ in
 
     environment.systemPackages = [ systemd ];
 
-    environment.etc = {
+    environment.etc = let
+      # generate contents for /etc/systemd/system-generators from
+      # systemd.generators and systemd.generator-packages
+      generators = pkgs.runCommand "system-generators" { packages = cfg.generator-packages; } ''
+        mkdir -p $out
+        for package in $packages
+        do
+          ln -s $package/lib/systemd/system-generators/* $out/
+        done;
+        ${concatStrings (mapAttrsToList (generator: target: "ln -s ${target} $out/${generator};\n") cfg.generators)}
+      '';
+    in ({
       "systemd/system".source = generateUnits "system" cfg.units upstreamSystemUnits upstreamSystemWants;
 
       "systemd/user".source = generateUnits "user" cfg.user.units upstreamUserUnits [];
@@ -667,7 +685,9 @@ in
 
         ${concatStringsSep "\n" cfg.tmpfiles.rules}
       '';
-    } // mapAttrs' (n: v: nameValuePair "systemd/system-generators/${n}" {"source"=v;}) cfg.generators;
+
+      "systemd/system-generators" = { source = generators; };
+    });
 
     system.activationScripts.systemd = stringAfter [ "groups" ]
       ''
diff --git a/pkgs/os-specific/linux/systemd/cryptsetup-generator.nix b/pkgs/os-specific/linux/systemd/cryptsetup-generator.nix
new file mode 100644
index 000000000000..2935990755c6
--- /dev/null
+++ b/pkgs/os-specific/linux/systemd/cryptsetup-generator.nix
@@ -0,0 +1,25 @@
+{ stdenv, systemd, cryptsetup }:
+
+assert stdenv.isLinux;
+
+stdenv.lib.overrideDerivation systemd (p: {
+  version = p.version;
+  name = "systemd-cryptsetup-generator";
+
+  nativeBuildInputs = p.nativeBuildInputs ++ [ cryptsetup ];
+  outputs = [ "out" ];
+
+  buildPhase = ''
+    make $makeFlags built-sources
+    make $makeFlags systemd-cryptsetup
+    make $makeFlags systemd-cryptsetup-generator
+  '';
+
+  installPhase = ''
+    mkdir -p $out/lib/systemd/
+    cp systemd-cryptsetup $out/lib/systemd/systemd-cryptsetup
+
+    mkdir -p $out/lib/systemd/system-generators/
+    cp systemd-cryptsetup-generator $out/lib/systemd/system-generators/systemd-cryptsetup-generator
+  '';
+})
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 8ca9370cc0e4..188788955ffe 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -11006,6 +11006,9 @@ in
     linuxHeaders = linuxHeaders_3_18;
   };
 
+  # standalone cryptsetup generator for systemd
+  systemd-cryptsetup-generator = callPackage ../os-specific/linux/systemd/cryptsetup-generator.nix { };
+
   # In nixos, you can set systemd.package = pkgs.systemd_with_lvm2 to get
   # LVM2 working in systemd.
   systemd_with_lvm2 = pkgs.lib.overrideDerivation pkgs.systemd (p: {