ADDENDUM TO INVESTMENT ADVISORY AGREEMENT Calvert Social Index Series, Inc. Calvert Social Index Fund

ADDENDUM TO INVESTMENT ADVISORY AGREEMENT

Xxxxxxx Social Index Series, Inc.

Xxxxxxx Social Index Fund

Xxxxxxx Investment Management, Inc. (“Xxxxxxx” or the “Advisor”) is the investment advisor to Xxxxxxx Social Index Fund (“Fund”), a series of Xxxxxxx Social Index Series, Inc.  Xxxxxxx has agreed with the Fund to contractually limit (direct/ or direct ordinary) net annual fund operating expenses of the Fund through January 31, 2014, as set forth below. This expense limitation does not limit the acquired fund fees and expenses incurred by a shareholder. Under the terms of the contractual expense limitation, operating expenses do not include interest expense, brokerage commissions, extraordinary expenses, performance fee adjustments, and taxes. To the extent any expense offset arrangement reduces Fund expenses, Xxxxxxx'x obligation under this agreement is reduced and Xxxxxxx shall also benefit from the expense offset arrangement. The below figure is expressed as a percentage of average net assets. 

	Class Y
Xxxxxxx Social Index Series, Inc.
Xxxxxxx Social Index Fund	0.60%

For Fund:	/s/ Xxxxxxx X. Xxxxxxxxx	For Xxxxxxx:	/s/ Xxxxxx X. Xxxxxxxxxxx
	Xxxxxxx X. Xxxxxxxxx, Vice President and		Xxxxxx X. Xxxxxxxxxxx, Executive Vice President
	Secretary		Chief Financial and Administrative Officer

Effective Date: July 13, 2012