diff --git a/gax/esm/src/fallbackServiceStub.ts b/gax/esm/src/fallbackServiceStub.ts
index bec89b47b..c87271130 100644
--- a/gax/esm/src/fallbackServiceStub.ts
+++ b/gax/esm/src/fallbackServiceStub.ts
@@ -42,7 +42,12 @@ export interface FallbackServiceStub {
 export type FetchParametersMethod = 'GET' | 'POST' | 'PUT' | 'PATCH' | 'DELETE';
 
 async function getNodeFetch() {
-  return await import('node-fetch');
+  const isEsm = true;
+  if (isEsm) {
+    return await import('node-fetch');
+  } else {
+    return require('node-fetch');
+  }
 }
 export interface FetchParameters {
   headers: {[key: string]: string};
diff --git a/gax/package.json b/gax/package.json
index ba855af14..25619ea2a 100644
--- a/gax/package.json
+++ b/gax/package.json
@@ -2,9 +2,9 @@
   "name": "google-gax",
   "version": "4.5.0",
   "description": "Google API Extensions",
-  "main": "./build/cjs/src/index.cjs",
+  "main": "./build/esm/src/index.js",
   "type": "module",
-  "types": "./build/cjs/src/index.d.ts",
+  "types": "./build/esm/src/index.d.ts",
   "files": [
     "build/esm",
     "build/cjs",