Amendments to Bylaws (Form 8-K)

On November 11, 2025, the Board of Directors (the "Board") of ClearSign Technologies Corporation (the "Company") adopted Amended and Restated Bylaws of the Company (as amended and restated, the "A&R Bylaws"), effective on such date. The amendments effected by the A&R Bylaws, among other things: (i) establish the required stockholder vote for the election of directors as the majority of the votes cast by the Company's stockholders, except that, if the number of nominees exceeds the number of directors to be elected, the directors will be elected by a plurality of the votes cast by the Company's stockholders; and (ii) modify certain procedures for business proposals and nominations to be brought by the Company's stockholders before an annual meeting of stockholders, including (x) an increase in the period in which the Company's Secretary (the "Secretary") is able to receive any such proposals or nominations to be properly brought before an annual meeting of the Company's stockholders and (y) more stringent requirements for stockholders submitting any such proposals or nominations, which includes providing documentary evidence (such as a broker statement or similar form) that, as of the date the proposals or nominations are submitted to the Secretary, the stockholder has continuously held certain beneficial ownership amounts of the Company's common stock, as further described in the A&R Bylaws, and a representation that such stockholder intends to maintain such beneficial ownership until the conclusion of the annual meeting.

The foregoing summary of, and the description of the amendments to, the A&R Bylaws does not purport to be complete and is qualified in its entirety by reference to the full text of the A&R Bylaws, copies of which are attached hereto as Exhibit 3.1, in unmarked form, and Exhibit 3.2, in redline form marked to show the amendments described above, and incorporated herein by reference.

On November 11, 2025, the Human Capital and Compensation Committee of the Board (the "Compensation Committee") approved and adopted certain modifications to the form of Stock Option Award Agreement (the "Revised Stock Option Award Agreement"), Restricted Stock Unit Award Agreement (the "Revised RSU Agreement") and Restricted Stock Award Agreement (the "Revised Restricted Stock Award Agreement," and together with the Revised Stock Option Award Agreement and the Revised RSU Agreement, the "Revised Award Agreements"), each to be used for future awards granted pursuant to the Company's 2021 Equity Incentive Plan, as it may be amended from time to time. Among other things, the modifications effected by the Revised Award Agreements: (i) change the governing law applicable to such award agreements from the State of Washington to the State of Delaware and (ii) change the jurisdiction and venue under such award agreements from the federal or state courts in the State of Washington to the federal or state courts in the State of Delaware, in each case to reflect the Company's state of incorporation.

The foregoing summary of the modifications made to the Revised Award Agreements does not purport to be complete and is qualified in its entirety by reference to the full text of the Revised Stock Option Award Agreement, Revised RSU Agreement and Revised Restricted Stock Award Agreement, copies of which are attached hereto as Exhibit 10.1, 10.2 and 10.3, respectively, and incorporated herein by reference.