diff --git a/packages/backend/test/mocks/rest/api/v1/users/register-user.ee.js b/packages/backend/test/mocks/rest/api/v1/users/register-user.ee.js
index cba1d815..bd06bbbc 100644
--- a/packages/backend/test/mocks/rest/api/v1/users/register-user.ee.js
+++ b/packages/backend/test/mocks/rest/api/v1/users/register-user.ee.js
@@ -11,7 +11,7 @@ const registerUserMock = (user) => {
   };
 
   if (appConfig.isCloud && user.trialExpiryDate) {
-    userData.trialExpiryDate = user.trial;
+    userData.trialExpiryDate = user.trialExpiryDate.toISOString();
   }
 
   return {