First Agreement to the Amended and Restated Supplemental Executive Retirement Plan Agreement, dated as of February 25, 2016, by and between HarborOne Bank and Joseph F. Casey

A. The Amended and Restated Supplemental Executive Retirement Plan Agreement (the"SERP') entered into February 25,2016, by and between HarborOne Bank ("HarborOne") andJoseph Casey (the "Executive") is hereby amended as fbllows, effective as olMarch 31,2022(the "Elfective Date")I . Section I (e) is hereby amended by adding the following at the end thereof:"In addition, notwithstanding the foregoing, an event shall not bedeemed a "Change in Control" for purposes ofthis Agreementunless such event also constitutes a change in the ownership oreffective control ofthe Company, or in the ownership ofasubstantial portion ofthe assets of the Company, as such change isdefined in Code Section 409A and regulations thereunder."2. Effective as ofthe first anniversary of the Effective Date, Section 1(o) is herebyamended by (i) deleting the phrase "the Executive attains age 65 while still employed byHarborOne" and replacing it with "lntentionally Omitted" and (ii) deleting the phrase "theprovided that such termination results in a Separation fiom Service" and replacing it with '1hetermination olthe Executive's employment other than a termination by HarborOne for Cause,provided that such termination results in a Separation from Service."3. Section 5 ofthe Agreement is hereby amended by adding the following newSection 5(c) at the end thereof:"(c) The Company and the Executive intend that the Agreementcomply with the provisions of Code Section 409A to prevent theinclusion in gross income ofany amounts deferred hereunder in ataxable year prior to the year in amounts are actually paid to theExecutive or Beneficiary. This Agreement shall be construed,ACTI\E/r r ###-###-####.2FIRSTAMENDMENTTOAMENDEDAND RESTATEDSUPPLEMENTAL EXECUTIVE RETIREMENT PLAN AGREEMENTvoluntary termination ofthe Executive's employment by HarborOne other than for Cause,

administered and govemed in a manner that affects such intent,and the Company shall not take any action that would beinconsistent therewith."4Section l2 is hereby amended by adding the following new paragraph at the end"The Company and the Executive may, subject to the terms hereol, amend thisAgreement to detay the timing "..-han;;';;';";;i paymenrs. Any suchamendment (i) must take effect not resi t,an i*.i*"i r zr months after theamendment is made: (ii) must, for benefits ai*iUr"Uf. a"" solely to the arrivalof a specified date. or on account of Separation frorn S"*i". or Change inControl, delay the commencement of distiibutions ]or- u .iri_u. of five (5)years from rhe date the first distribution "r. "JgrJIy ."ri"orr.d ,o be madel riiirmust. for benetits distributabte due ror.ry ro tt.'ui;';i;;p;;t-t";;;;],;Jmade nor Iess than rwelve ( l2) months uefore iir,i'ir,i", ,, scheduled to begin:and (iv) may nor acceterate rhe time ",,.k;;i.;;;nli[,riuu,ion...thereol-:B. The effective date of this First Amendment shall be March 31,2022.c' Except as otherwise amended herein, the Agreement is confirmed in all other respects.Executed effective as ofthe date set fo(h above by the parties thereto and, in the case ofHARBORONE BANKBy:Title: ChiefExecutive OtficerEXECUTIVE:HarborOne, its duly authorized officer.2ACTM/I ###-###-####.2F. Casey