Dyne Therapeutics, Inc.

STATE OF DELAWARE

CERTIFICATE OF AMENDMENT

OF CERTIFICATE OF INCORPORATION

Pursuant to Section 242 of the General Corporation Law of the State of Delaware, Dyne Therapeutics, Inc., a corporation organized under and existing by virtue of the General Corporation Law of the State of Delaware (“DGCL”), DOES HEREBY CERTIFY:

The name of the corporation is Dyne Therapeutics, Inc. (the “Corporation”).

The date of filing the original Certificate of Incorporation of this Corporation with the Secretary of State of the State of Delaware was December 1, 2017.

Resolutions were duly adopted by the Board of Directors of the Corporation setting forth this proposed Amendment to the Certificate of Incorporation and declaring said amendment to be advisable and calling for the consideration and approval thereof at a meeting of the stockholders of the Corporation.

The Certificate of Incorporation is hereby amended by amending and restating the first paragraph of Article FOURTH in its entirety as follows:

“FOURTH: The total number of shares of all classes of stock that the Corporation shall have authority to issue is 410,000,000 shares, consisting of (i) 400,000,000 shares of Common Stock, $.0001 par value per share (“Common Stock”), and (ii) 10,000,000 shares of Preferred Stock, $.0001 par value per share (“Preferred Stock”).”

The foregoing amendment was effected pursuant to a resolution of the Board of Directors of said corporation.

Thereafter, pursuant to a resolution by the Board of Directors, this Certificate of Amendment was submitted to the stockholders of the Corporation for their approval in accordance with the provisions of Section 242 of the DGCL. Accordingly, said proposed amendment has been adopted in accordance with Section 242 of the DGCL.

IN WITNESS WHEREOF, Dyne Therapeutics, Inc. has caused this certificate to be signed this [] day of [], 2026

By: _______________________

Name:

Title: