SharePoint 2013 Hybrid Search

Hi,

I am planning to implement Hybrid Search for our O365 tenant and SP2013 environment. I see a requirement mentioned in MS guidance that SP2013 web applications should use "Integrated Windows Authentication using NTLM" authentication type but in our SP on-premise environment each web application is using Kerberos (Negotiate), so do we need to extend these web applications and configure to use NTLM or this Negotiate (fallback to NTLM) will work as it is?

- Prashant.