diff --git a/x-pack/test/lists_api_integration/security_and_spaces/tests/create_lists.ts b/x-pack/test/lists_api_integration/security_and_spaces/tests/create_lists.ts
index 0372e93f8ba465..1385662f40c208 100644
--- a/x-pack/test/lists_api_integration/security_and_spaces/tests/create_lists.ts
+++ b/x-pack/test/lists_api_integration/security_and_spaces/tests/create_lists.ts
@@ -43,15 +43,35 @@ export default ({ getService }: FtrProviderContext) => {
         await deleteListsIndex(supertest);
       });
 
-      it('should create a list with a list_id', async () => {
+      it('should create a simple list with a list_id', async () => {
         const { body } = await supertest
           .post(LIST_URL)
           .set('kbn-xsrf', 'true')
-          .send(getCreateMinimalListSchemaMock());
+          .send(getCreateMinimalListSchemaMock())
+          .expect(200);
 
         const bodyToCompare = removeServerGeneratedProperties(body);
         expect(bodyToCompare).to.eql(getListResponseMockWithoutAutoGeneratedValues());
       });
+
+      it('should cause a 409 conflict if we attempt to create the same list_id twice', async () => {
+        await supertest
+          .post(LIST_URL)
+          .set('kbn-xsrf', 'true')
+          .send(getCreateMinimalListSchemaMock())
+          .expect(200);
+
+        const { body } = await supertest
+          .post(LIST_URL)
+          .set('kbn-xsrf', 'true')
+          .send(getCreateMinimalListSchemaMock())
+          .expect(409);
+
+        expect(body).to.eql({
+          message: 'list id: "some-list-id" already exists',
+          status_code: 409,
+        });
+      });
     });
   });
 };