Exhibit 3.1

CERTIFICATE OF AMENDMENT TO THE

RESTATED CERTIFICATE OF INCORPORATION

OF

ANSYS, INC.

ANSYS, Inc., a corporation organized and existing under the laws of the State of Delaware (the “Corporation”), hereby certifies that the Restated Certificate of Incorporation of the Corporation dated as of July 11, 1996, as amended by a Certificate of Amendment filed on June 20, 2006 (the “Restated Certificate”) is hereby amended as follows:

“The total number of shares of capital stock which the Corporation shall have the authority to issue is Three Hundred Two Million (302,000,000) shares, of which (i) Two Million (2,000,000) shares shall be Undesignated Preferred Stock, par value $.01 per share (the “Preferred Stock”), and (ii) Three Hundred Million (300,000,000) shares shall be Common Stock, par value $.01 per share (the “Common Stock”). As set forth in this Article IV, the Board of Directors or any authorized committee thereof is authorized from time to time to establish and designate one or more series of Preferred Stock, to fix and determine the variations in the relative rights and preferences as between the different series of Preferred Stock in the manner hereinafter set forth in this Article IV, and to fix or alter the number of shares comprising any such series and the designation thereof to the extent permitted by law.”

IN WITNESS WHEREOF, the Corporation has caused this Certificate of Amendment of the Restated Certificate of Incorporation to be signed by James E. Cashman III, its President and Chief Executive Officer, this 11th day of May, 2011, which signature constitutes the affirmation or acknowledgment of such officer, under penalties of perjury, that this instrument is the act and deed of the Corporation, and that the facts stated herein are true.