5.37% Uses in Operating Expenses and Taxes Clause

Operating Expenses and Taxes from Amendment to Lease

This FIRST AMENDMENT TO LEASE (this Amendment) is entered into and effective as of the 19th day of October, 2015 (the First Amendment Effective Date) by and between RIVERWORKS WATERTOWN HOLDINGS, LLC, a Delaware limited liability company, as landlord (Landlord), as successor-in-interest to Farley White Aetna Mills, LLC, having an address for purposes hereof at One Market Plaza, Spear Tower, Suite 4125, San Francisco, California 94105, and MIMECAST NORTH AMERICA, INC., a Delaware corporation, as tenant (Tenant), having an address for purposes hereof at 480 Pleasant Street, Watertown, Massachusetts 02472.

Operating Expenses and Taxes. Notwithstanding anything contained in the Existing Lease to the contrary, from and after the First Amendment Effective Date and during the First Expansion Premises Term, Tenant shall continue to pay Operating Expenses and Taxes for the Existing Premises in accordance with all terms and provisions contained in the Existing Lease. In addition to and without in any way limiting such payments, with respect to the First Expansion Premises Tenant shall pay to Landlord, commencing on the First Expansion Premises Rent Commencement Date and through the expiration or earlier termination of tire First Expansion Premises Term; (a) Tenants First Expansion Premises Percentage (as hereinafter defined) of the amount by which the annual Operating Expenses exceed the Operating Expenses for calendar year 2016; and (b) Tenants First Expansion Premises Percentage of any increase in Taxes over the Taxes attributable to fiscal year 2016 (i.e., July 1, 2015 through June 30, 2016), in each case upon all the same terms and provisions applicable to Tenants payment on account of Taxes and Operating Expenses for the Existing Premises, as set forth in the Existing Lease. For purposes hereof: (i) Tenants First Expansion Premises Percentage shall mean 5.37%; and (ii) a fiscal year shall be deemed to fall within the Term and/or the First Expansion Premises Term (as applicable) if such fiscal year falls within the Term or First Expansion Premises Term in whole or in part, but in the latter case the Taxes for such year shall be pro rated on a per diem basis.