Fourth Amendment to Lease between Mitel Networks Corporation and KRP Properties a division of Wesley Clover International Corporation made as of September 15, 2017

Exhibit 10.12(d)

THIS AGREEMENT made as of the 15^th day of September, 2017

BETWEEN:

KRP PROPERTIES

a division of Wesley Clover International Corporation

(Hereinafter called the “Landlord”)

OF THE FIRST PART

AND:

MITEL NETWORKS CORPORATION

(Hereinafter called the “Tenant”)

OF THE SECOND PART

FOURTH AMENDMENT TO LEASE

WHEREAS by written lease dated November 1, 2010, as amended by: 1) Partial Surrender of Lease and First Amendment to Lease dated November 7, 2013; 2) Second Amendment to Lease made March 3, 2014; and 3) Third Amendment to Lease made February 11, 2015 (the lease as so amended being herein called the “Lease”), the Tenant is leasing the following premises from the Landlord, which premises have been certified by the Landlord:

of the building municipally known as 350 Legget Drive, in the City of Ottawa (the “350 Building”), and

of the building municipally known as 390 March Road, in the City of Ottawa (the “390 Building”), and

of the building municipally known as 340 Legget Drive, in the City of Ottawa (the “340 Building”),

(herein collectively referred to as the “Leased Premises”).

AND WHEREAS Kanata Research Park Corporation amalgamated with Wesley Clover International Corporation pursuant to a Certificate of Amalgamation dated January 1, 2017, continuing as Wesley Clover International Corporation;

AND WHEREAS the parties agree to amend the Lease to provide for the Tenant’s lease of storage premises located in the basement of the 350 Building;

NOW THEREFORE in consideration of the rents, covenants, conditions and agreements herein contained, the Landlord and Tenant covenant and agree to amend the Lease, effective January 1, 2015, as follows:

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of the building municipally known as 350 Legget Drive, in the City of Ottawa (the “350 Building”), and

of the building municipally known as 390 March Road, in the City of Ottawa (the “390 Building”), and

of the building municipally known as 340 Legget Drive, in the City of Ottawa (the “340 Building”),

(herein collectively referred to as the “Leased Premises”). The 340 Building, 350 Building, and 390 Building are collectively referred to as the “Building”, which buildings are erected on the lands (herein called the “Lands”) described in Schedule “A” annexed hereto. The Leased Premises are more particularly outlined in bold on the floor plans annexed hereto and marked as Schedules “B1” to “B11” inclusively.”

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SAVE AND EXCEPT as set out herein, all other terms and conditions of the Lease shall remain unchanged and shall apply during the Term and any extension thereof, and all capitalized terms used herein shall have the same meaning as in the Lease.

IN WITNESS WHEREOF the parties hereto have affixed their corporate seals duly attested to by the hands of their authorized signing officers.

SIGNED, SEALED AND DELIVERED in the Presence of:

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SCHEDULE “B1”

FLOOR PLAN OF 350 LOWER LEVEL PREMISES AND 350 BASEMENT STORAGE

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