diff --git a/modules/dream2nix/builtins-derivation/default.nix b/modules/dream2nix/builtins-derivation/default.nix
index e0a7730f..e695cf67 100644
--- a/modules/dream2nix/builtins-derivation/default.nix
+++ b/modules/dream2nix/builtins-derivation/default.nix
@@ -1,6 +1,50 @@
 {
+  config,
+  lib,
+  ...
+}: let
+  l = lib // builtins;
+  t = l.types;
+
+  cfg = config.builtins-derivation;
+
+  outputs = l.unique cfg.outputs;
+
+  keepArg = key: val: val != null;
+
+  finalArgs = l.filterAttrs keepArg cfg;
+
+  # ensure that none of the env variables collide with the top-level options
+  envChecked =
+    l.mapAttrs
+    (key: val:
+      if config.builtins-derivation.${key} or false
+      then throw (envCollisionError key)
+      else val)
+    config.env;
+
+  # generates error message for env variable collision
+  envCollisionError = key: ''
+    Error while evaluating definitions for derivation ${config.name}
+    The environment variable defined via `env.${key}' collides with the option builtins-derivation.`${key}'.
+    Specify the top-level option instead, or rename the environment variable.
+  '';
+in {
   imports = [
-    ./implementation.nix
     ./interface.nix
+    ../core
+    ../package-func
   ];
+
+  config.package-func.outputs = cfg.outputs;
+
+  config.package-func.func = lib.mkDefault builtins.derivation;
+
+  config.package-func.args =
+    envChecked
+    // finalArgs
+    // {
+      inherit outputs;
+      inherit (config.public) name;
+    };
 }
diff --git a/modules/dream2nix/builtins-derivation/implementation.nix b/modules/dream2nix/builtins-derivation/implementation.nix
deleted file mode 100644
index 633acc1b..00000000
--- a/modules/dream2nix/builtins-derivation/implementation.nix
+++ /dev/null
@@ -1,49 +0,0 @@
-{
-  config,
-  lib,
-  ...
-}: let
-  l = lib // builtins;
-  t = l.types;
-
-  cfg = config.builtins-derivation;
-
-  outputs = l.unique cfg.outputs;
-
-  keepArg = key: val: val != null;
-
-  finalArgs = l.filterAttrs keepArg cfg;
-
-  # ensure that none of the env variables collide with the top-level options
-  envChecked =
-    l.mapAttrs
-    (key: val:
-      if config.builtins-derivation.${key} or false
-      then throw (envCollisionError key)
-      else val)
-    config.env;
-
-  # generates error message for env variable collision
-  envCollisionError = key: ''
-    Error while evaluating definitions for derivation ${config.name}
-    The environment variable defined via `env.${key}' collides with the option builtins-derivation.`${key}'.
-    Specify the top-level option instead, or rename the environment variable.
-  '';
-in {
-  imports = [
-    ../core
-    ../package-func
-  ];
-
-  config.package-func.outputs = cfg.outputs;
-
-  config.package-func.func = lib.mkDefault builtins.derivation;
-
-  config.package-func.args =
-    envChecked
-    // finalArgs
-    // {
-      inherit outputs;
-      inherit (config.public) name;
-    };
-}
diff --git a/modules/dream2nix/mkDerivation/default.nix b/modules/dream2nix/mkDerivation/default.nix
index e0a7730f..1ad09bce 100644
--- a/modules/dream2nix/mkDerivation/default.nix
+++ b/modules/dream2nix/mkDerivation/default.nix
@@ -1,6 +1,68 @@
 {
+  config,
+  lib,
+  ...
+}: let
+  l = lib // builtins;
+  t = l.types;
+
+  cfg = config.mkDerivation;
+
+  outputs = l.unique cfg.outputs;
+
+  keepArg = key: val: val != null;
+
+  finalArgs = l.filterAttrs keepArg cfg;
+
+  # ensure that none of the env variables collide with the top-level options
+  envChecked =
+    l.mapAttrs
+    (key: val:
+      if config.mkDerivation ? ${key}
+      then throw (envCollisionError key)
+      else val)
+    config.env;
+
+  # generates error message for env variable collision
+  envCollisionError = key: ''
+    Error while evaluating definitions for derivation ${config.name}
+    The environment variable defined via `env.${key}' collides with the option mkDerivation.`${key}'.
+    Specify the top-level option instead, or rename the environment variable.
+  '';
+
+  public =
+    # meta
+    (l.optionalAttrs (cfg.passthru ? meta) {
+      inherit (cfg.passthru) meta;
+    })
+    # tests
+    // (l.optionalAttrs (cfg.passthru ? tests) {
+      inherit (cfg.passthru) tests;
+    });
+in {
   imports = [
-    ./implementation.nix
     ./interface.nix
+    ../core
+    ../package-func
   ];
+
+  config.package-func.outputs = cfg.outputs;
+
+  config.package-func.func = lib.mkDefault config.deps.stdenv.mkDerivation;
+
+  # add mkDerivation specific derivation attributes
+  config.public = public;
+
+  config.package-func.args =
+    envChecked
+    // finalArgs
+    // {
+      inherit outputs;
+      inherit (config.public) version;
+      pname = config.name;
+    };
+
+  config.deps = {nixpkgs, ...}: {
+    stdenv = lib.mkOverride 1050 nixpkgs.stdenv;
+  };
 }
diff --git a/modules/dream2nix/mkDerivation/implementation.nix b/modules/dream2nix/mkDerivation/implementation.nix
deleted file mode 100644
index dae74a2c..00000000
--- a/modules/dream2nix/mkDerivation/implementation.nix
+++ /dev/null
@@ -1,67 +0,0 @@
-{
-  config,
-  lib,
-  ...
-}: let
-  l = lib // builtins;
-  t = l.types;
-
-  cfg = config.mkDerivation;
-
-  outputs = l.unique cfg.outputs;
-
-  keepArg = key: val: val != null;
-
-  finalArgs = l.filterAttrs keepArg cfg;
-
-  # ensure that none of the env variables collide with the top-level options
-  envChecked =
-    l.mapAttrs
-    (key: val:
-      if config.mkDerivation ? ${key}
-      then throw (envCollisionError key)
-      else val)
-    config.env;
-
-  # generates error message for env variable collision
-  envCollisionError = key: ''
-    Error while evaluating definitions for derivation ${config.name}
-    The environment variable defined via `env.${key}' collides with the option mkDerivation.`${key}'.
-    Specify the top-level option instead, or rename the environment variable.
-  '';
-
-  public =
-    # meta
-    (l.optionalAttrs (cfg.passthru ? meta) {
-      inherit (cfg.passthru) meta;
-    })
-    # tests
-    // (l.optionalAttrs (cfg.passthru ? tests) {
-      inherit (cfg.passthru) tests;
-    });
-in {
-  imports = [
-    ../core
-    ../package-func
-  ];
-
-  config.package-func.outputs = cfg.outputs;
-
-  config.package-func.func = lib.mkDefault config.deps.stdenv.mkDerivation;
-
-  # add mkDerivation specific derivation attributes
-  config.public = public;
-
-  config.package-func.args =
-    envChecked
-    // finalArgs
-    // {
-      inherit outputs;
-      inherit (config.public) version;
-      pname = config.name;
-    };
-
-  config.deps = {nixpkgs, ...}: {
-    stdenv = lib.mkOverride 1050 nixpkgs.stdenv;
-  };
-}