diff --git a/lib/types.d.ts b/lib/types.d.ts
index a83db020..ea8243d0 100644
--- a/lib/types.d.ts
+++ b/lib/types.d.ts
@@ -152,6 +152,7 @@ export interface TransformOptions {
   filename?: string;
   ts?: boolean;
   retainLines?: boolean;
+  interopDefault?: boolean;
   async: boolean;
   [key: string]: any;
 }
diff --git a/src/babel.ts b/src/babel.ts
index ff825f75..fb754abf 100644
--- a/src/babel.ts
+++ b/src/babel.ts
@@ -32,7 +32,14 @@ export default function transform(opts: TransformOptions): TransformResult {
     cwd: "/",
     ...opts.babel,
     plugins: [
-      [transformModulesPlugin, { allowTopLevelThis: true, async: opts.async }],
+      [
+        transformModulesPlugin,
+        {
+          allowTopLevelThis: true,
+          noInterop: !opts.interopDefault,
+          async: opts.async,
+        },
+      ],
       [TransformImportMetaPlugin, { filename: opts.filename }],
       [syntaxClassPropertiesPlugin],
       [transformExportNamespaceFromPlugin],
diff --git a/src/transform.ts b/src/transform.ts
index e0c7d9fe..78509319 100644
--- a/src/transform.ts
+++ b/src/transform.ts
@@ -3,7 +3,7 @@ import { getCache } from "./cache";
 import { debug } from "./utils";
 
 export function transform(ctx: Context, topts: TransformOptions): string {
-  let code = getCache(ctx, topts.filename, topts.source, topts.async, () => {
+  let code = getCache(ctx, topts, () => {
     const res = ctx.opts.transform!({
       ...ctx.opts.transformOptions,
       babel: {
@@ -15,6 +15,7 @@ export function transform(ctx: Context, topts: TransformOptions): string {
           : {}),
         ...ctx.opts.transformOptions?.babel,
       },
+      interopDefault: ctx.opts.interopDefault,
       ...topts,
     });
     if (res.error && ctx.opts.debug) {