diff --git a/packages/docz-core/src/Bundler.ts b/packages/docz-core/src/Bundler.ts
index 2a49bdf90..28065c4bc 100644
--- a/packages/docz-core/src/Bundler.ts
+++ b/packages/docz-core/src/Bundler.ts
@@ -20,6 +20,8 @@ export interface BundlerConstructor<Config> {
   build: BuildFn<Config>
 }
 
+const IS_PROD = process.env.NODE_ENV === 'production'
+
 export class Bundler<C = any> {
   private readonly args: Args
   private config: C
@@ -36,7 +38,8 @@ export class Bundler<C = any> {
   }
 
   public getConfig(): C {
-    return this.mountConfig(this.config)
+    const config = this.args.modifyBundlerConfig(this.config, !IS_PROD)
+    return this.mountConfig(config)
   }
 
   public async createServer(config: C): Promise<BundlerServer> {
@@ -48,10 +51,9 @@ export class Bundler<C = any> {
   }
 
   private mountConfig(config: C): any {
-    const { plugins, env } = this.args
-    const dev = env === 'development'
+    const { plugins } = this.args
     const reduce = Plugin.reduceFromPlugins<C>(plugins)
 
-    return reduce('modifyBundlerConfig', config, dev)
+    return reduce('modifyBundlerConfig', config, !IS_PROD)
   }
 }
diff --git a/packages/docz-core/src/commands/args.ts b/packages/docz-core/src/commands/args.ts
index 86e0bfe60..44de2d214 100644
--- a/packages/docz-core/src/commands/args.ts
+++ b/packages/docz-core/src/commands/args.ts
@@ -22,14 +22,17 @@ export interface Argv {
   theme: string
 }
 
+export interface ThemeConfig {
+  [key: string]: any
+}
+
 export interface Config extends Argv {
   paths: Paths
   plugins?: Plugin[]
   mdPlugins: any[]
   hastPlugins: any[]
-  themeConfig?: {
-    [key: string]: any
-  }
+  themeConfig: ThemeConfig
+  modifyBundlerConfig<C>(config: C, dev: boolean): C
 }
 
 export const args = (yargs: any) => {
diff --git a/packages/docz-core/src/utils/load-config.ts b/packages/docz-core/src/utils/load-config.ts
index efcaff177..2618f2cdd 100644
--- a/packages/docz-core/src/utils/load-config.ts
+++ b/packages/docz-core/src/utils/load-config.ts
@@ -15,6 +15,7 @@ export const loadConfig = (args: Config): Config => {
     mdPlugins: [],
     hastPlugins: [],
     themeConfig: {},
+    modifyBundlerConfig: (config: any) => config,
   })
 
   const reduce = Plugin.reduceFromPlugins<Config>(config.plugins)