diff --git a/packages/pack/src/actions/main.ts b/packages/pack/src/actions/main.ts
index 3630367..1ec3323 100644
--- a/packages/pack/src/actions/main.ts
+++ b/packages/pack/src/actions/main.ts
@@ -59,7 +59,7 @@ module.exports = async function action(specifiedEntries: string[], options: any
     } = {}) => {
         let eachOutExt = eachOptions.ext || eachOptions.outfile && upath.extname(eachOptions.outfile) || undefined
         const outExtension = { '.css': '.css' }
-        const external = [
+        let external = [
             ...externalDependencies,
             ...options.external
         ]
@@ -89,6 +89,9 @@ module.exports = async function action(specifiedEntries: string[], options: any
                 }
             })
         }
+        if (eachOptions.bundle && options.forceIifeBundle) {
+            external = []
+        }
         const eachOutdir = eachOptions.outdir || options.outdir
 
         /**
diff --git a/packages/pack/tests/force-iife-bundle/package.json b/packages/pack/tests/force-iife-bundle/package.json
new file mode 100644
index 0000000..271ae16
--- /dev/null
+++ b/packages/pack/tests/force-iife-bundle/package.json
@@ -0,0 +1,12 @@
+{
+    "name": "@test/force-iife-bundle",
+    "version": "1.0.0",
+    "private": true,
+    "browser": "./dist/iife.bundle.js",
+    "files": [
+        "dist"
+    ],
+    "dependencies": {
+        "server-only": "^0.0.1"
+    }
+}
\ No newline at end of file
diff --git a/packages/pack/tests/force-iife-bundle/src/iife.ts b/packages/pack/tests/force-iife-bundle/src/iife.ts
new file mode 100644
index 0000000..2fac8dc
--- /dev/null
+++ b/packages/pack/tests/force-iife-bundle/src/iife.ts
@@ -0,0 +1 @@
+import 'server-only'
\ No newline at end of file
diff --git a/packages/pack/tests/force-iife-bundle/test.ts b/packages/pack/tests/force-iife-bundle/test.ts
new file mode 100644
index 0000000..dcbff5e
--- /dev/null
+++ b/packages/pack/tests/force-iife-bundle/test.ts
@@ -0,0 +1,7 @@
+import { execSync } from 'node:child_process'
+import { expectFileIncludes } from '../../../../utils/expect-file-includes'
+
+it('force to bundle iife', () => {
+    execSync('tsx ../../../techor/src/bin pack', { cwd: __dirname, stdio: 'pipe' })
+    expectFileIncludes('dist/iife.bundle.js', ['(()=>{throw new Error("This module cannot be imported from a Client Component module. It should only be used from a Server Component.");})();'], { cwd: __dirname })
+})
\ No newline at end of file
diff --git a/packages/pack/tests/force-iife-bundle/tsconfig.json b/packages/pack/tests/force-iife-bundle/tsconfig.json
new file mode 100644
index 0000000..b94c20e
--- /dev/null
+++ b/packages/pack/tests/force-iife-bundle/tsconfig.json
@@ -0,0 +1,13 @@
+{
+    "extends": "../../../../tsconfig.json",
+    "compilerOptions": {
+        "baseUrl": ".",
+        "outDir": "dist",
+    },
+    "include": [
+        "src/**/*"
+    ],
+    "exclude": [
+        "src/**/*.test.ts"
+    ]
+}
\ No newline at end of file
diff --git a/packages/pack/tests/pnpm-lock.yaml b/packages/pack/tests/pnpm-lock.yaml
index 6829e5e..03040b7 100644
--- a/packages/pack/tests/pnpm-lock.yaml
+++ b/packages/pack/tests/pnpm-lock.yaml
@@ -49,6 +49,12 @@ importers:
         specifier: ''
         version: 2.4.6
 
+  force-iife-bundle:
+    dependencies:
+      server-only:
+        specifier: ^0.0.1
+        version: 0.0.1
+
   mjs:
     dependencies:
       server-only:
diff --git a/packages/techor/src/bin/index.ts b/packages/techor/src/bin/index.ts
index ee768d6..9a36ee2 100755
--- a/packages/techor/src/bin/index.ts
+++ b/packages/techor/src/bin/index.ts
@@ -34,6 +34,7 @@ program.command('pack [entryPaths...]')
     .option('--declare', 'Emit typescript declarations')
     .option('--no-minify', 'OFF: Minify the generated code')
     .option('--no-clean', 'OFF: Clean up the previous output directory before the build starts')
+    .option('--no-force-iife-bundle', 'OFF: No external packages when the output format is iife')
     .action(async function (args, options) {
         try {
             const action = require(