diff --git a/README.md b/README.md
index 52270e4..fee6ef5 100644
--- a/README.md
+++ b/README.md
@@ -58,6 +58,18 @@ export default {
 };
 ```
 
+You can also configure `externals` for all packages like this:
+
+```ts
+// prebundle.config.mjs
+export default {
+  externals: {
+    webpack: '../webpack',
+  },
+  dependencies: [{ name: 'foo' }, { name: 'foo' }],
+};
+```
+
 ### minify
 
 Whether to minify the code, default `true`.
diff --git a/src/helper.ts b/src/helper.ts
index c933dda..ba004a5 100644
--- a/src/helper.ts
+++ b/src/helper.ts
@@ -1,7 +1,7 @@
 import { dirname, join } from 'node:path';
 import fs from 'fs-extra';
 import { cwd, DIST_DIR } from './constant.js';
-import type { DependencyConfig, ParsedTask } from './types.js';
+import type { Config, DependencyConfig, ParsedTask } from './types.js';
 import { createRequire } from 'node:module';
 
 const require = createRequire(import.meta.url);
@@ -23,7 +23,7 @@ export function findDepPath(name: string) {
 export const resolveConfig = async () => {
   const configPath = join(cwd, 'prebundle.config.mjs');
   const config = await import(configPath);
-  return config.default;
+  return config.default as Config;
 };
 
 export function parseTasks(dependencies: Array<string | DependencyConfig>) {
diff --git a/src/index.ts b/src/index.ts
index dba58b8..8e7bd47 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -6,7 +6,7 @@ export async function run() {
   const parsedTasks = parseTasks(config.dependencies);
 
   for (const task of parsedTasks) {
-    await prebundle(task);
+    await prebundle(task, config.externals);
   }
 }
 
diff --git a/src/prebundle.ts b/src/prebundle.ts
index 741f5ef..017eff7 100644
--- a/src/prebundle.ts
+++ b/src/prebundle.ts
@@ -145,7 +145,10 @@ function renameDistFolder(task: ParsedTask) {
 
 const pkgName = process.argv[2];
 
-export async function prebundle(task: ParsedTask) {
+export async function prebundle(
+  task: ParsedTask,
+  commonExternals: Record<string, string>,
+) {
   if (pkgName && task.depName !== pkgName) {
     return;
   }
@@ -163,6 +166,7 @@ export async function prebundle(task: ParsedTask) {
     target: 'es2019',
     externals: {
       ...DEFAULT_EXTERNALS,
+      ...commonExternals,
       ...task.externals,
     },
     assetBuilds: false,
diff --git a/src/types.ts b/src/types.ts
index 61968ae..fb6db55 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -23,6 +23,11 @@ export type DependencyConfig = {
 };
 
 export type Config = {
+  /**
+   * Configure externals for all packages,
+   * will be merged with dependencies[i].externals.
+   */
+  externals: Record<string, string>;
   dependencies: Array<string | DependencyConfig>;
 };