diff --git a/packages/destination-actions/src/destinations/loops/createOrUpdateContact/__tests__/index.test.ts b/packages/destination-actions/src/destinations/loops/createOrUpdateContact/__tests__/index.test.ts
index db31d2bb92..5536bba7a0 100644
--- a/packages/destination-actions/src/destinations/loops/createOrUpdateContact/__tests__/index.test.ts
+++ b/packages/destination-actions/src/destinations/loops/createOrUpdateContact/__tests__/index.test.ts
@@ -22,6 +22,7 @@ describe('Loops.createOrUpdateContact', () => {
   })
 
   it('should work', async () => {
+    /* Event data going into Segment */
     const testPayloadIn = {
       createdAt: '2025-05-05T14:17:38.089Z',
       customAttributes: {
@@ -35,6 +36,7 @@ describe('Loops.createOrUpdateContact', () => {
       userGroup: 'Alum',
       userId: 'some-id-1'
     }
+    /* Processed data coming out of Segment to the API */
     const testPayloadOut = {
       createdAt: '2025-05-05T14:17:38.089Z',
       favoriteColor: 'blue',
@@ -115,7 +117,7 @@ describe('Loops.createOrUpdateContact', () => {
     })
   })
 
-  it('should work with mailingLists data', async () => {
+  it('should work with mailingLists array', async () => {
     const testPayloadIn = {
       email: 'test@example.com',
       userId: 'some-id-2',
@@ -149,4 +151,61 @@ describe('Loops.createOrUpdateContact', () => {
       id: 'someId'
     })
   })
+
+  it('should work with empty mailingLists object', async () => {
+    const testPayloadIn = {
+      email: 'test@example.com',
+      userId: 'some-id-2',
+      mailingLists: []
+    }
+    const testPayloadOut = {
+      email: 'test@example.com',
+      userId: 'some-id-2',
+      mailingLists: {}
+    }
+    nock('https://app.loops.so/api/v1').put('/contacts/update', testPayloadOut).reply(200, {
+      success: true,
+      id: 'someId'
+    })
+
+    const responses = await testDestination.testAction('createOrUpdateContact', {
+      mapping: testPayloadIn,
+      settings: { apiKey: LOOPS_API_KEY }
+    })
+
+    expect(responses.length).toBe(1)
+    expect(responses[0].status).toBe(200)
+    expect(responses[0].data).toStrictEqual({
+      success: true,
+      id: 'someId'
+    })
+  })
+
+  it('should work with no mailingLists object', async () => {
+    const testPayloadIn = {
+      email: 'test@example.com',
+      userId: 'some-id-2'
+    }
+    const testPayloadOut = {
+      email: 'test@example.com',
+      userId: 'some-id-2',
+      mailingLists: {}
+    }
+    nock('https://app.loops.so/api/v1').put('/contacts/update', testPayloadOut).reply(200, {
+      success: true,
+      id: 'someId'
+    })
+
+    const responses = await testDestination.testAction('createOrUpdateContact', {
+      mapping: testPayloadIn,
+      settings: { apiKey: LOOPS_API_KEY }
+    })
+
+    expect(responses.length).toBe(1)
+    expect(responses[0].status).toBe(200)
+    expect(responses[0].data).toStrictEqual({
+      success: true,
+      id: 'someId'
+    })
+  })
 })