diff --git a/.github/workflows/integration-tests.yml b/.github/workflows/integration-tests.yml
index 9b5eb36..38b2d5c 100644
--- a/.github/workflows/integration-tests.yml
+++ b/.github/workflows/integration-tests.yml
@@ -69,6 +69,8 @@ jobs:
           logTime: "false"
 
       - run: curl -vvvv http://localhost:3000/pages/AMD.html && cat log.txt
+      - run: curl -vvvv http://localhost:3000/pages/ESM.html && cat log.txt
+      - run: curl -vvvv http://localhost:3000/pages/ESM-dynamic.html && cat log.txt
 
       - name: Run Browser integration tests
         run: npm run test:integration:browser
diff --git a/tests/integration/browser/tests/esm-dynamic/import.test.ts b/tests/integration/browser/tests/esm-dynamic/import.test.ts
index 16e3ba0..37aa8a6 100644
--- a/tests/integration/browser/tests/esm-dynamic/import.test.ts
+++ b/tests/integration/browser/tests/esm-dynamic/import.test.ts
@@ -20,18 +20,19 @@ type Window = globalThis.Window & {
 
 describe('AMD import validation', () => {
   beforeAll(async () => {
-    await page.goto('http://localhost:3000/pages/ESM.html');
+    await page.goto('http://localhost:3000/pages/ESM-dynamic.html');
     await page.waitForFunction(function () { return typeof (window as Window).mailgunClient !== 'undefined'; });
     await page.waitForFunction(function () { return typeof (window as Window).packageExport !== 'undefined'; });
     await page.waitForFunction(function () { return typeof (window as Window).definitionsExport !== 'undefined'; });
   });
 
-  test('AMD package exports function', async () => {
-    const isFunction = await page.evaluate(() => (typeof (window as Window).packageExport === 'function'));
-    expect(isFunction).toBe(true);
+  test('ESM-dynamic package exports object', async () => {
+    const exported = await page.evaluate(() => ((window as Window).packageExport));
+    expect(exported).toEqual(expect.any(Object));
+    expect(exported).toHaveProperty('default');
   });
 
-  test('AMD definitions exports object', async () => {
+  test('ESM-dynamic definitions exports object', async () => {
     const definitionsExport = await page.evaluate(() => (window as Window).definitionsExport);
     expect(typeof definitionsExport).toBe('object');
     expect(definitionsExport).toEqual(expect.objectContaining({
@@ -40,7 +41,7 @@ describe('AMD import validation', () => {
     }));
   });
 
-  test('AMD client has expected structure', async () => {
+  test('ESM-dynamic client has expected structure', async () => {
     const client = await page.evaluate(() => (window as Window).mailgunClient);
     const expected = ['request', 'domains', 'webhooks', 'events', 'stats', 'suppressions', 'messages', 'routes', 'ips', 'ip_pools', 'lists', 'validate'];
     expect(client).toBeDefined();
diff --git a/tests/integration/browser/tests/esm-dynamic/messages.test.ts b/tests/integration/browser/tests/esm-dynamic/messages.test.ts
index f91ce86..4e13b1d 100644
--- a/tests/integration/browser/tests/esm-dynamic/messages.test.ts
+++ b/tests/integration/browser/tests/esm-dynamic/messages.test.ts
@@ -17,9 +17,9 @@ type ExtendedWindow = globalThis.Window & {
   packageExport?: object
 };
 
-describe('Send message functionality (AMD)', () => {
+describe('Send message functionality (ESM-dynamic)', () => {
   beforeAll(async () => {
-    await page.goto('http://localhost:3000/pages/ESM.html');
+    await page.goto('http://localhost:3000/pages/ESM-dynamic.html');
     await page.waitForFunction(function () { return typeof (window as ExtendedWindow).mailgunClient !== 'undefined'; });
     await page.setRequestInterception(true);
 
@@ -41,7 +41,7 @@ describe('Send message functionality (AMD)', () => {
     await page.setRequestInterception(false);
   });
 
-  test('Sends plain email (AMD)', async () => {
+  test('Sends plain email (ESM-dynamic)', async () => {
     const result = await page.evaluate(
       (domain, messageData) => (window as ExtendedWindow)?.mailgunClient?.messages.create(
         domain,
@@ -62,7 +62,7 @@ describe('Send message functionality (AMD)', () => {
     });
   });
 
-  test('Sends mime email (AMD)', async () => {
+  test('Sends mime email (ESM-dynamic)', async () => {
     const result = await page.evaluate(
       (domain, messageData) => (window as ExtendedWindow).mailgunClient?.messages.create(
         domain,
@@ -83,7 +83,7 @@ describe('Send message functionality (AMD)', () => {
     });
   });
 
-  test('Sends an attachment (AMD)', async () => {
+  test('Sends an attachment (ESM-dynamic)', async () => {
     await page.waitForSelector('input[type=file]', { timeout: 3000 });
     const input = await page.$('input[type=file]');
     expect(input).toBeTruthy();
diff --git a/tests/integration/browser/tests/esm/import.test.ts b/tests/integration/browser/tests/esm/import.test.ts
index 16e3ba0..940ee52 100644
--- a/tests/integration/browser/tests/esm/import.test.ts
+++ b/tests/integration/browser/tests/esm/import.test.ts
@@ -26,12 +26,12 @@ describe('AMD import validation', () => {
     await page.waitForFunction(function () { return typeof (window as Window).definitionsExport !== 'undefined'; });
   });
 
-  test('AMD package exports function', async () => {
+  test('ESM package exports function', async () => {
     const isFunction = await page.evaluate(() => (typeof (window as Window).packageExport === 'function'));
     expect(isFunction).toBe(true);
   });
 
-  test('AMD definitions exports object', async () => {
+  test('ESM definitions exports object', async () => {
     const definitionsExport = await page.evaluate(() => (window as Window).definitionsExport);
     expect(typeof definitionsExport).toBe('object');
     expect(definitionsExport).toEqual(expect.objectContaining({
@@ -40,7 +40,7 @@ describe('AMD import validation', () => {
     }));
   });
 
-  test('AMD client has expected structure', async () => {
+  test('ESM client has expected structure', async () => {
     const client = await page.evaluate(() => (window as Window).mailgunClient);
     const expected = ['request', 'domains', 'webhooks', 'events', 'stats', 'suppressions', 'messages', 'routes', 'ips', 'ip_pools', 'lists', 'validate'];
     expect(client).toBeDefined();
diff --git a/tests/integration/browser/tests/esm/messages.test.ts b/tests/integration/browser/tests/esm/messages.test.ts
index e38e7d3..9a3866f 100644
--- a/tests/integration/browser/tests/esm/messages.test.ts
+++ b/tests/integration/browser/tests/esm/messages.test.ts
@@ -17,9 +17,9 @@ type ExtendedWindow = globalThis.Window & {
   packageExport?: object
 };
 
-describe('Send message functionality (AMD)', () => {
+describe('Send message functionality (ESM)', () => {
   beforeAll(async () => {
-    await page.goto('http://localhost:3000/pages/esm-dynamic.html');
+    await page.goto('http://localhost:3000/pages/ESM.html');
     await page.waitForFunction(function () { return typeof (window as ExtendedWindow).mailgunClient !== 'undefined'; });
     await page.setRequestInterception(true);
 
@@ -41,7 +41,7 @@ describe('Send message functionality (AMD)', () => {
     await page.setRequestInterception(false);
   });
 
-  test('Sends plain email (AMD)', async () => {
+  test('Sends plain email (ESM)', async () => {
     const result = await page.evaluate(
       (domain, messageData) => (window as ExtendedWindow)?.mailgunClient?.messages.create(
         domain,
@@ -62,7 +62,7 @@ describe('Send message functionality (AMD)', () => {
     });
   });
 
-  test('Sends mime email (AMD)', async () => {
+  test('Sends mime email (ESM)', async () => {
     const result = await page.evaluate(
       (domain, messageData) => (window as ExtendedWindow).mailgunClient?.messages.create(
         domain,
@@ -83,7 +83,7 @@ describe('Send message functionality (AMD)', () => {
     });
   });
 
-  test('Sends an attachment (AMD)', async () => {
+  test('Sends an attachment (ESM)', async () => {
     await page.waitForSelector('input[type=file]', { timeout: 3000 });
     const input = await page.$('input[type=file]');
     expect(input).toBeTruthy();