diff --git a/examples/official-storybook/main.ts b/examples/official-storybook/main.ts
index e72009a04f20..3522ffe7dae3 100644
--- a/examples/official-storybook/main.ts
+++ b/examples/official-storybook/main.ts
@@ -2,7 +2,7 @@
 
 import type { StorybookConfig } from '@storybook/react/types';
 
-module.exports = {
+const config: StorybookConfig = {
   stories: [
     // FIXME: Breaks e2e tests './intro.stories.mdx',
     '../../lib/ui/src/**/*.stories.@(js|tsx|mdx)',
@@ -35,4 +35,6 @@ module.exports = {
     builder: 'webpack4',
   },
   logLevel: 'debug',
-} as StorybookConfig;
+};
+
+module.exports = config;
diff --git a/examples/react-ts-webpack4/main.ts b/examples/react-ts-webpack4/main.ts
index 14131c236a8e..9f01df4c63e7 100644
--- a/examples/react-ts-webpack4/main.ts
+++ b/examples/react-ts-webpack4/main.ts
@@ -1,6 +1,6 @@
 import type { StorybookConfig } from '@storybook/react/types';
 
-module.exports = {
+const config: StorybookConfig = {
   stories: ['./src/*.stories.*'],
   logLevel: 'debug',
   addons: [
@@ -27,4 +27,6 @@ module.exports = {
       propFilter: (prop) => ['label', 'disabled'].includes(prop.name),
     },
   },
-} as StorybookConfig;
+};
+
+module.exports = config;
diff --git a/examples/react-ts/main.ts b/examples/react-ts/main.ts
index 3427cbbc2528..e702ca4c15ba 100644
--- a/examples/react-ts/main.ts
+++ b/examples/react-ts/main.ts
@@ -1,6 +1,6 @@
 import type { StorybookConfig } from '@storybook/react/types';
 
-module.exports = {
+const config: StorybookConfig = {
   stories: ['./src/*.stories.*'],
   logLevel: 'debug',
   addons: [
@@ -31,4 +31,6 @@ module.exports = {
   features: {
     postcss: false,
   },
-} as StorybookConfig;
+};
+
+module.exports = config;
diff --git a/lib/core-common/src/types.ts b/lib/core-common/src/types.ts
index 50d18720484b..c5b420b673be 100644
--- a/lib/core-common/src/types.ts
+++ b/lib/core-common/src/types.ts
@@ -229,6 +229,14 @@ export interface StorybookConfig {
         options?: any;
       }
   >;
+  core?: CoreConfig;
+  logLevel?: string;
+  /**
+   * Allows to disable deprecated implicit PostCSS loader.
+   */
+  features?: {
+    postcss?: boolean;
+  };
   /**
    * Tells Storybook where to find stories.
    *