diff --git a/packages/core/src/config.ts b/packages/core/src/config.ts
index cd9350a72..1d3f355fd 100644
--- a/packages/core/src/config.ts
+++ b/packages/core/src/config.ts
@@ -227,21 +227,27 @@ export const composeAutoExternalConfig = (options: {
     return {};
   }
 
+  // User externals configuration has higher priority than autoExternal
+  // eg: autoExternal: ['react'], user: output: { externals: { react: 'react-1' } }
+  // Only handle the case where the externals type is object, string / string[] does not need to be processed, other types are too complex.
+  const userExternalKeys =
+    userExternals && isObject(userExternals) ? Object.keys(userExternals) : [];
+
   const externalOptions = {
     dependencies: true,
+    optionalDependencies: true,
     peerDependencies: true,
     devDependencies: false,
     ...(autoExternal === true ? {} : autoExternal),
   };
 
-  // User externals configuration has higher priority than autoExternal
-  // eg: autoExternal: ['react'], user: output: { externals: { react: 'react-1' } }
-  // Only handle the case where the externals type is object, string / string[] does not need to be processed, other types are too complex.
-  const userExternalKeys =
-    userExternals && isObject(userExternals) ? Object.keys(userExternals) : [];
-
   const externals = (
-    ['dependencies', 'peerDependencies', 'devDependencies'] as const
+    [
+      'dependencies',
+      'peerDependencies',
+      'devDependencies',
+      'optionalDependencies',
+    ] as const
   )
     .reduce<string[]>((prev, type) => {
       if (externalOptions[type]) {
diff --git a/packages/core/src/types/utils.ts b/packages/core/src/types/utils.ts
index 8b3d31293..bc99ee756 100644
--- a/packages/core/src/types/utils.ts
+++ b/packages/core/src/types/utils.ts
@@ -1,6 +1,7 @@
 export type PkgJson = {
+  type?: 'module' | 'commonjs';
   dependencies?: Record<string, string>;
   peerDependencies?: Record<string, string>;
   devDependencies?: Record<string, string>;
-  [key: string]: unknown;
+  optionalDependencies?: Record<string, string>;
 };
diff --git a/packages/plugin-dts/src/dts.ts b/packages/plugin-dts/src/dts.ts
index d30252052..d689f335a 100644
--- a/packages/plugin-dts/src/dts.ts
+++ b/packages/plugin-dts/src/dts.ts
@@ -26,6 +26,7 @@ export const calcBundledPackages = (options: {
     dependencies?: Record<string, string>;
     peerDependencies?: Record<string, string>;
     devDependencies?: Record<string, string>;
+    optionalDependencies?: Record<string, string>;
   };
 
   try {
@@ -42,6 +43,7 @@ export const calcBundledPackages = (options: {
     ? {
         dependencies: true,
         peerDependencies: true,
+        optionalDependencies: true,
         devDependencies: false,
         ...(autoExternal === true ? {} : autoExternal),
       }