diff --git a/lib/cli/src/GeneratorOptions.ts b/lib/cli/src/GeneratorOptions.ts
deleted file mode 100644
index d9f2b3e01ec6..000000000000
--- a/lib/cli/src/GeneratorOptions.ts
+++ /dev/null
@@ -1,5 +0,0 @@
-import { StoryFormat } from './project_types';
-
-export type GeneratorOptions = {
-  storyFormat: StoryFormat;
-};
diff --git a/lib/cli/src/generators/ANGULAR/index.ts b/lib/cli/src/generators/ANGULAR/index.ts
index 22de407c3c99..cc9d5921366f 100644
--- a/lib/cli/src/generators/ANGULAR/index.ts
+++ b/lib/cli/src/generators/ANGULAR/index.ts
@@ -16,7 +16,7 @@ import {
 } from '../../helpers';
 import { StoryFormat } from '../../project_types';
 import { NpmOptions } from '../../NpmOptions';
-import { GeneratorOptions } from '../../GeneratorOptions';
+import { Generator, GeneratorOptions } from '../Generator';
 
 async function addDependencies(npmOptions: NpmOptions, { storyFormat }: GeneratorOptions) {
   const packages = [
@@ -64,7 +64,7 @@ function editAngularAppTsConfig() {
   writeFileAsJson(getAngularAppTsConfigPath(), tsConfigJson);
 }
 
-export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions) => {
+const generator: Generator = async (npmOptions, { storyFormat }) => {
   if (!isDefaultProjectSet()) {
     throw new Error(
       'Could not find a default project in your Angular workspace.\nSet a defaultProject in your angular.json and re-run the installation.'
@@ -77,3 +77,5 @@ export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions)
   editAngularAppTsConfig();
   editStorybookTsConfig(path.resolve('./.storybook/tsconfig.json'));
 };
+
+export default generator;
diff --git a/lib/cli/src/generators/AURELIA/index.ts b/lib/cli/src/generators/AURELIA/index.ts
index 282232a7dd8b..3f7362f13759 100644
--- a/lib/cli/src/generators/AURELIA/index.ts
+++ b/lib/cli/src/generators/AURELIA/index.ts
@@ -8,8 +8,7 @@ import {
   copyTemplate,
   readFileAsJson,
 } from '../../helpers';
-import { NpmOptions } from '../../NpmOptions';
-import { GeneratorOptions } from '../../GeneratorOptions';
+import { Generator } from '../Generator';
 import { StoryFormat } from '../../project_types';
 
 function addStorybookExcludeGlobToTsConfig() {
@@ -27,11 +26,7 @@ function addStorybookExcludeGlobToTsConfig() {
   tsConfigJson.exclude = [...exclude, glob];
   writeFileAsJson('tsconfig.json', tsConfigJson);
 }
-
-export default async (
-  npmOptions: NpmOptions,
-  { storyFormat = StoryFormat.CSF }: GeneratorOptions
-) => {
+const generator: Generator = async (npmOptions, { storyFormat = StoryFormat.CSF }) => {
   copyTemplate(__dirname, storyFormat);
   const packages = [
     '@storybook/aurelia',
@@ -62,3 +57,5 @@ export default async (
   const babelDependencies = await getBabelDependencies(npmOptions, packageJson);
   installDependencies({ ...npmOptions, packageJson }, [...versionedPackages, ...babelDependencies]);
 };
+
+export default generator;
diff --git a/lib/cli/src/generators/EMBER/index.ts b/lib/cli/src/generators/EMBER/index.ts
index 79e151ada78a..874e81e6e2e7 100644
--- a/lib/cli/src/generators/EMBER/index.ts
+++ b/lib/cli/src/generators/EMBER/index.ts
@@ -6,10 +6,9 @@ import {
   installDependencies,
   copyTemplate,
 } from '../../helpers';
-import { NpmOptions } from '../../NpmOptions';
-import { GeneratorOptions } from '../../GeneratorOptions';
+import { Generator } from '../Generator';
 
-export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions) => {
+const generator: Generator = async (npmOptions, { storyFormat }) => {
   const [
     storybookVersion,
     babelPluginEmberModulePolyfillVersion,
@@ -58,3 +57,5 @@ export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions)
     ...babelDependencies,
   ]);
 };
+
+export default generator;
diff --git a/lib/cli/src/generators/Generator.ts b/lib/cli/src/generators/Generator.ts
new file mode 100644
index 000000000000..b6143c0c92dc
--- /dev/null
+++ b/lib/cli/src/generators/Generator.ts
@@ -0,0 +1,8 @@
+import { NpmOptions } from '../NpmOptions';
+import { StoryFormat } from '../project_types';
+
+export type GeneratorOptions = {
+  storyFormat: StoryFormat;
+};
+
+export type Generator = (npmOptions: NpmOptions, options: GeneratorOptions) => Promise<void>;
diff --git a/lib/cli/src/generators/HTML/index.ts b/lib/cli/src/generators/HTML/index.ts
index 4932497a1062..25d850192b6c 100755
--- a/lib/cli/src/generators/HTML/index.ts
+++ b/lib/cli/src/generators/HTML/index.ts
@@ -7,10 +7,9 @@ import {
   copyTemplate,
 } from '../../helpers';
 import { StoryFormat } from '../../project_types';
-import { NpmOptions } from '../../NpmOptions';
-import { GeneratorOptions } from '../../GeneratorOptions';
+import { Generator } from '../Generator';
 
-export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions) => {
+const generator: Generator = async (npmOptions, { storyFormat }) => {
   const packages = ['@storybook/html', '@storybook/addon-actions', '@storybook/addon-links'];
 
   const versionedPackages = await getVersionedPackages(npmOptions, ...packages);
@@ -35,3 +34,5 @@ export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions)
 
   installDependencies({ ...npmOptions, packageJson }, [...versionedPackages, ...babelDependencies]);
 };
+
+export default generator;
diff --git a/lib/cli/src/generators/MARIONETTE/index.ts b/lib/cli/src/generators/MARIONETTE/index.ts
index 88dd0e5c8218..e3ce805931a8 100644
--- a/lib/cli/src/generators/MARIONETTE/index.ts
+++ b/lib/cli/src/generators/MARIONETTE/index.ts
@@ -7,9 +7,9 @@ import {
   installDependencies,
   retrievePackageJson,
 } from '../../helpers';
-import { NpmOptions } from '../../NpmOptions';
+import { Generator } from '../Generator';
 
-export default async (npmOptions: NpmOptions) => {
+const generator: Generator = async (npmOptions) => {
   const storybookVersion = await getVersion(npmOptions, '@storybook/marionette');
   fse.copySync(path.resolve(__dirname, 'template/'), '.', { overwrite: true });
 
@@ -31,3 +31,5 @@ export default async (npmOptions: NpmOptions) => {
     ...babelDependencies,
   ]);
 };
+
+export default generator;
diff --git a/lib/cli/src/generators/MARKO/index.ts b/lib/cli/src/generators/MARKO/index.ts
index 43a8b6a285e4..b8a3bc0e40e1 100644
--- a/lib/cli/src/generators/MARKO/index.ts
+++ b/lib/cli/src/generators/MARKO/index.ts
@@ -6,10 +6,9 @@ import {
   installDependencies,
   copyTemplate,
 } from '../../helpers';
-import { NpmOptions } from '../../NpmOptions';
-import { GeneratorOptions } from '../../GeneratorOptions';
+import { Generator } from '../Generator';
 
-export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions) => {
+const generator: Generator = async (npmOptions, { storyFormat }) => {
   const [storybookVersion, addonActionVersion, addonKnobsVersion] = await getVersions(
     npmOptions,
     '@storybook/marko',
@@ -39,3 +38,5 @@ export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions)
     ...babelDependencies,
   ]);
 };
+
+export default generator;
diff --git a/lib/cli/src/generators/METEOR/index.ts b/lib/cli/src/generators/METEOR/index.ts
index d9decd69e534..6420a01f0b03 100644
--- a/lib/cli/src/generators/METEOR/index.ts
+++ b/lib/cli/src/generators/METEOR/index.ts
@@ -8,10 +8,9 @@ import {
   installDependencies,
   copyTemplate,
 } from '../../helpers';
-import { NpmOptions } from '../../NpmOptions';
-import { GeneratorOptions } from '../../GeneratorOptions';
+import { Generator } from '../Generator';
 
-export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions) => {
+const generator: Generator = async (npmOptions, { storyFormat }) => {
   const [
     storybookVersion,
     actionsVersion,
@@ -96,3 +95,5 @@ export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions)
 
   installDependencies({ ...npmOptions, packageJson }, [...devDependencies, ...babelDependencies]);
 };
+
+export default generator;
diff --git a/lib/cli/src/generators/MITHRIL/index.ts b/lib/cli/src/generators/MITHRIL/index.ts
index aaca46d1c7b7..d6bff9454643 100644
--- a/lib/cli/src/generators/MITHRIL/index.ts
+++ b/lib/cli/src/generators/MITHRIL/index.ts
@@ -6,10 +6,9 @@ import {
   installDependencies,
   copyTemplate,
 } from '../../helpers';
-import { NpmOptions } from '../../NpmOptions';
-import { GeneratorOptions } from '../../GeneratorOptions';
+import { Generator } from '../Generator';
 
-export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions) => {
+const generator: Generator = async (npmOptions, { storyFormat }) => {
   const [
     storybookVersion,
     actionsVersion,
@@ -49,3 +48,5 @@ export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions)
     ...babelDependencies,
   ]);
 };
+
+export default generator;
diff --git a/lib/cli/src/generators/PREACT/index.ts b/lib/cli/src/generators/PREACT/index.ts
index 7d732258998a..42c9eb416c9d 100644
--- a/lib/cli/src/generators/PREACT/index.ts
+++ b/lib/cli/src/generators/PREACT/index.ts
@@ -6,10 +6,9 @@ import {
   installDependencies,
   copyTemplate,
 } from '../../helpers';
-import { NpmOptions } from '../../NpmOptions';
-import { GeneratorOptions } from '../../GeneratorOptions';
+import { Generator } from '../Generator';
 
-export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions) => {
+const generator: Generator = async (npmOptions, { storyFormat }) => {
   const [storybookVersion, actionsVersion, linksVersion, addonsVersion] = await getVersions(
     npmOptions,
     '@storybook/preact',
@@ -41,3 +40,5 @@ export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions)
     ...babelDependencies,
   ]);
 };
+
+export default generator;
diff --git a/lib/cli/src/generators/RAX/index.ts b/lib/cli/src/generators/RAX/index.ts
index a7ef43519a4f..4ac18e259ab9 100644
--- a/lib/cli/src/generators/RAX/index.ts
+++ b/lib/cli/src/generators/RAX/index.ts
@@ -6,10 +6,9 @@ import {
   installDependencies,
   copyTemplate,
 } from '../../helpers';
-import { NpmOptions } from '../../NpmOptions';
-import { GeneratorOptions } from '../../GeneratorOptions';
+import { Generator } from '../Generator';
 
-export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions) => {
+const generator: Generator = async (npmOptions, { storyFormat }) => {
   const [
     storybookVersion,
     actionsVersion,
@@ -59,3 +58,5 @@ export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions)
     ...babelDependencies,
   ]);
 };
+
+export default generator;
diff --git a/lib/cli/src/generators/REACT/index.ts b/lib/cli/src/generators/REACT/index.ts
index 01e192db510a..586dac39814b 100644
--- a/lib/cli/src/generators/REACT/index.ts
+++ b/lib/cli/src/generators/REACT/index.ts
@@ -7,10 +7,9 @@ import {
   copyTemplate,
 } from '../../helpers';
 import { StoryFormat } from '../../project_types';
-import { NpmOptions } from '../../NpmOptions';
-import { GeneratorOptions } from '../../GeneratorOptions';
+import { Generator } from '../Generator';
 
-export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions) => {
+const generator: Generator = async (npmOptions, { storyFormat }) => {
   const packages = [
     '@storybook/react',
     '@storybook/addon-actions',
@@ -40,3 +39,5 @@ export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions)
 
   installDependencies({ ...npmOptions, packageJson }, [...versionedPackages, ...babelDependencies]);
 };
+
+export default generator;
diff --git a/lib/cli/src/generators/REACT_NATIVE/index.ts b/lib/cli/src/generators/REACT_NATIVE/index.ts
index 8ce6b66124bf..aad02bcb16c6 100644
--- a/lib/cli/src/generators/REACT_NATIVE/index.ts
+++ b/lib/cli/src/generators/REACT_NATIVE/index.ts
@@ -10,7 +10,7 @@ import {
   copyTemplate,
 } from '../../helpers';
 import { NpmOptions } from '../../NpmOptions';
-import { GeneratorOptions } from '../../GeneratorOptions';
+import { GeneratorOptions } from '../Generator';
 
 export default async (
   npmOptions: NpmOptions,
diff --git a/lib/cli/src/generators/REACT_SCRIPTS/index.ts b/lib/cli/src/generators/REACT_SCRIPTS/index.ts
index efebc3350fe3..cc43eafdb98e 100644
--- a/lib/cli/src/generators/REACT_SCRIPTS/index.ts
+++ b/lib/cli/src/generators/REACT_SCRIPTS/index.ts
@@ -9,10 +9,9 @@ import {
   copyTemplate,
 } from '../../helpers';
 import { StoryFormat } from '../../project_types';
-import { NpmOptions } from '../../NpmOptions';
-import { GeneratorOptions } from '../../GeneratorOptions';
+import { Generator } from '../Generator';
 
-export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions) => {
+const generator: Generator = async (npmOptions, { storyFormat }) => {
   const packages = [
     '@storybook/react',
     '@storybook/preset-create-react-app',
@@ -50,3 +49,5 @@ export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions)
 
   installDependencies({ ...npmOptions, packageJson }, [...versionedPackages, ...babelDependencies]);
 };
+
+export default generator;
diff --git a/lib/cli/src/generators/RIOT/index.ts b/lib/cli/src/generators/RIOT/index.ts
index 3bfc24ef2eae..2c624431018a 100644
--- a/lib/cli/src/generators/RIOT/index.ts
+++ b/lib/cli/src/generators/RIOT/index.ts
@@ -6,10 +6,9 @@ import {
   installDependencies,
   copyTemplate,
 } from '../../helpers';
-import { NpmOptions } from '../../NpmOptions';
-import { GeneratorOptions } from '../../GeneratorOptions';
+import { Generator } from '../Generator';
 
-export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions) => {
+const generator: Generator = async (npmOptions, { storyFormat }) => {
   const [
     storybookVersion,
     actionsVersion,
@@ -54,3 +53,5 @@ export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions)
 
   installDependencies({ ...npmOptions, packageJson }, [...dependencies, ...babelDependencies]);
 };
+
+export default generator;
diff --git a/lib/cli/src/generators/SFC_VUE/index.ts b/lib/cli/src/generators/SFC_VUE/index.ts
index 6f6ec71e5573..0f85dbce6b12 100644
--- a/lib/cli/src/generators/SFC_VUE/index.ts
+++ b/lib/cli/src/generators/SFC_VUE/index.ts
@@ -7,10 +7,9 @@ import {
   copyTemplate,
 } from '../../helpers';
 import { StoryFormat } from '../../project_types';
-import { NpmOptions } from '../../NpmOptions';
-import { GeneratorOptions } from '../../GeneratorOptions';
+import { Generator } from '../Generator';
 
-export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions) => {
+const generator: Generator = async (npmOptions, { storyFormat }) => {
   const packages = [
     '@storybook/vue',
     '@storybook/addon-actions',
@@ -39,3 +38,5 @@ export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions)
 
   installDependencies({ ...npmOptions, packageJson }, [...versionedPackages, ...babelDependencies]);
 };
+
+export default generator;
diff --git a/lib/cli/src/generators/SVELTE/index.ts b/lib/cli/src/generators/SVELTE/index.ts
index 1ba6778fe3b3..9da7bfa15463 100644
--- a/lib/cli/src/generators/SVELTE/index.ts
+++ b/lib/cli/src/generators/SVELTE/index.ts
@@ -6,10 +6,9 @@ import {
   installDependencies,
   copyTemplate,
 } from '../../helpers';
-import { NpmOptions } from '../../NpmOptions';
-import { GeneratorOptions } from '../../GeneratorOptions';
+import { Generator } from '../Generator';
 
-export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions) => {
+const generator: Generator = async (npmOptions, { storyFormat }) => {
   const [
     storybookVersion,
     actionsVersion,
@@ -52,3 +51,5 @@ export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions)
     ...babelDependencies,
   ]);
 };
+
+export default generator;
diff --git a/lib/cli/src/generators/VUE/index.ts b/lib/cli/src/generators/VUE/index.ts
index 6254b35f923b..01e33e1978cb 100644
--- a/lib/cli/src/generators/VUE/index.ts
+++ b/lib/cli/src/generators/VUE/index.ts
@@ -9,10 +9,9 @@ import {
   copyTemplate,
 } from '../../helpers';
 import { StoryFormat } from '../../project_types';
-import { NpmOptions } from '../../NpmOptions';
-import { GeneratorOptions } from '../../GeneratorOptions';
+import { Generator } from '../Generator';
 
-export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions) => {
+const generator: Generator = async (npmOptions, { storyFormat }) => {
   const packages = [
     '@storybook/vue',
     '@storybook/addon-actions',
@@ -59,3 +58,5 @@ export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions)
   // see: https://github.com/storybookjs/storybook/issues/4475#issuecomment-432141296
   installDependencies({ ...npmOptions, packageJson }, [...versionedPackages, ...babelDependencies]);
 };
+
+export default generator;
diff --git a/lib/cli/src/generators/WEB-COMPONENTS/index.ts b/lib/cli/src/generators/WEB-COMPONENTS/index.ts
index defc5a13d987..373eac327a67 100755
--- a/lib/cli/src/generators/WEB-COMPONENTS/index.ts
+++ b/lib/cli/src/generators/WEB-COMPONENTS/index.ts
@@ -8,10 +8,9 @@ import {
   installDependencies,
 } from '../../helpers';
 import { StoryFormat } from '../../project_types';
-import { NpmOptions } from '../../NpmOptions';
-import { GeneratorOptions } from '../../GeneratorOptions';
+import { Generator } from '../Generator';
 
-export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions) => {
+const generator: Generator = async (npmOptions, { storyFormat }) => {
   const packages = [
     '@storybook/web-components',
     '@storybook/addon-actions',
@@ -42,3 +41,5 @@ export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions)
 
   installDependencies({ ...npmOptions, packageJson }, [...versionedPackages, ...babelDependencies]);
 };
+
+export default generator;
diff --git a/lib/cli/src/generators/WEBPACK_REACT/index.ts b/lib/cli/src/generators/WEBPACK_REACT/index.ts
index 2a4eec9a6390..75bec7324ed2 100644
--- a/lib/cli/src/generators/WEBPACK_REACT/index.ts
+++ b/lib/cli/src/generators/WEBPACK_REACT/index.ts
@@ -7,10 +7,9 @@ import {
   copyTemplate,
 } from '../../helpers';
 import { StoryFormat } from '../../project_types';
-import { NpmOptions } from '../../NpmOptions';
-import { GeneratorOptions } from '../../GeneratorOptions';
+import { Generator } from '../Generator';
 
-export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions) => {
+const generator: Generator = async (npmOptions, { storyFormat }) => {
   const packages = [
     '@storybook/react',
     '@storybook/addon-actions',
@@ -39,3 +38,5 @@ export default async (npmOptions: NpmOptions, { storyFormat }: GeneratorOptions)
 
   installDependencies({ ...npmOptions, packageJson }, [...versionedPackages, ...babelDependencies]);
 };
+
+export default generator;
diff --git a/lib/cli/src/initiate.ts b/lib/cli/src/initiate.ts
index ee63341f287f..1c080c029a09 100644
--- a/lib/cli/src/initiate.ts
+++ b/lib/cli/src/initiate.ts
@@ -180,7 +180,7 @@ const installStorybook = (projectType: ProjectType, options: CommandOptions): Pr
           .then(end);
 
       case ProjectType.MARIONETTE:
-        return marionetteGenerator(npmOptions)
+        return marionetteGenerator(npmOptions, generatorOptions)
           .then(commandLog('Adding storybook support to your "Marionette.js" app'))
           .then(end);