Exhibit 10.1


 





THIRD AMENDMENT TO LEASE


 


THIS THIRD AMENDMENT TO LEASE (this “Third
Amendment”), dated as of the 18th day of July, 2019, is entered into by and between BOEING EMPLOYEES’ CREDIT UNION,
a Washington state chartered credit union (“Landlord”), and CLEARSIGN COMBUSTION CORPORATION, a Washington corporation
(“Tenant”).


 


RECITALS


 


A.       RREEF
America REIT II Corp. MMMM7 Washington (“RREEF”) and Tenant entered into that certain Lease dated August 19, 2011,
as amended by that certain Commencement Date Memorandum dated November 1, 2011, that certain First Amendment to Lease dated
December 17, 2013, and that certain Second Amendment to Lease dated October 18, 2016 (collectively, the “Lease”).
Landlord is the successor-in-interest to RREEF.


 


B.       The
Lease pertains to approximately 9,200 square feet of space located in Building 1 of Gateway Corporate Center, having an address
of 12870 Interurban Avenue South, Tukwila, Washington 98168 (the “Premises”), as more fully described in the Lease.


 


C.       Landlord
and Tenant desire to extend the Term of the Lease, change the rent schedule and otherwise modify the terms and conditions of the
Lease, as more fully set forth below.


 


AMENDMENT


 


NOW, THEREFORE, in consideration of the
mutual covenants and conditions contained herein and other good and valuable consideration, the receipt and sufficiency of which
is hereby acknowledged, the parties agree as follows:


 


		1.	Definitions. Unless otherwise specifically set forth herein, all capitalized terms used
shall have the meanings attributed to them in the Lease.



 


		2.	Term. The Term of the Lease is hereby extended for a period of three (3) years and
two (2) months, commencing on April 1, 2020, and terminating on May 31, 2023.



 


		3.	Rent Schedule. The rent schedule for the period from April 1, 2020, through May 31,
2023, shall be as follows:



 


	Period	Rentable Square Footage	Annual Rent Per Square Foot	Annual Rent	Monthly Installment of Rent
	from	through
	4/1/2020	5/31/2020	9,200	$0.00	$0.00	$0.00*
	6/1/2020	3/31/2021	9,200	$17.64	$162,288.00	$13,524.00
	4/1/2021	3/31/2022	9,200	$18.17	$167,160.00	$13,930.00
	4/1/2022	3/31/2023	9,200	$18.71	$172,176.00	$14,348.00
	4/1/2023	5/31/2023	9,200	$19.28	$177,336.00	$14,778.00



 

		*	Tenant shall be responsible for the payment of Tenant’s Proportionate
Share of Expenses and Taxes during the period that the Monthly Installment of Rent is abated.



 






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		4.	Counterparts. This Third Amendment may be executed in counterparts, each of which shall
be deemed an original but all of which together shall be deemed to be one and the same agreement.



 


		5.	Effect of Amendment; Incorporation. Except as expressly modified herein, all terms and conditions
of the Lease remain in full force and effect and are hereby ratified and confirmed.



 


[signature page and
notary acknowledgments follow]


 






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IN WITNESS WHEREOF, Landlord
and Tenant have executed this Third Amendment as of the day and year first written above.


 





	LANDLORD:	 	TENANT:
	 	 	 
	BOEING EMPLOYEES’ CREDIT UNION, 	 	CLEARSIGN COMBUSTION CORPORATION,
	a Washington state chartered credit union	 	a Washington corporation
	 	 	 	 	 
	By:  	/s/
    Gregg Kats	 	By:  	/s/ Brian G. Fike
	 	 	 	 	 
	Name:  	Gregg Kats	 	Name:  	Brian G. Fike
	 	 	 	 	 
	Title:  	SVP Administration & Operation	 	Title:  	Interim Chief Financial
    Officer
	 	 	 	 	 
	Date:  	8/26/2019	 	Date:  	8/09/2019







 






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CORPORATE ACKNOWLEDGMENT


 





	STATE OF WASHINGTON	)
	 	)  ss.
	COUNTY OF KING	)


  


On this 09 day
of August, 2019, before me, the undersigned, a Notary Public in and for the State of Washington, personally appeared Brian Fike,
to me known or shown through satisfactory evidence to be the Tenant of CLEARSIGN COMBUSTION CORPORATION, a Washington state chartered credit union, and
acknowledged to me that ____ executed the foregoing instrument on behalf of said party freely and voluntarily for the uses and
purposes therein mentioned.


 


Witness my hand and
official seal the day and year in this certificate first above written.


 





	 	Olga
    Stryzheus
	 	(Signature)
	 	 
	 	Olga
    Stryzheus
	 	(Please print name legibly)
	 	 
	 	Notary Public in and for the State of Washington,
	 	My commission expires 09/15/2021




 


CORPORATE ACKNOWLEDGMENT


 





	STATE OF WASHINGTON	)
	 	)  ss.
	COUNTY OF KING	)


 


On this 26 day of
August, 2019, before me, the undersigned, a Notary Public in and for the State of Washington, personally appeared Gregg Kats,
to me known or shown through satisfactory evidence to be the SVP Administration & Operation of BOEING EMPLOYEES’ CREDIT UNION, a
Washington corporation, and acknowledged to me that ____ executed the same on behalf of said corporation freely and
voluntarily for the uses and purposes therein mentioned.


 


Witness my hand and
official seal the day and year in this certificate first above written.


 





	 	Katie
    Vereechen
	 	(Signature)
	 	 
	 	Katie
    Vereechen
	 	(Please print name legibly)
	 	 
	 	Notary Public in and for the State of Washington,
	 	My commission expires 11/25/2020





 








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