Exhibit 10.3

AMENDMENT TO THE

SUPPLEMENTAL INCOME PLAN OF

THE PBSJ CORPORATION

EFFECTIVE JANUARY 12, 1988

MODIFIED SEPTEMBER 27, 1995

WHEREAS,
The PBSJ Corporation (the Corporation) previously adopted the Supplemental Income Plan (the Plan), effective as of January 12, 1988.

WHEREAS, the Corporation reserves the right to amend the Plan.

WHEREAS, the Corporation
desires to amend the Plan to comply with Section 409A of the Internal Revenue Code (the Code).

WHEREAS, the
Corporation recently adopted the Key Employee Capital Accumulation Plan, effective as of September 30, 2008 as a continuation of the non-stock benefits under the Plan with respect to active employees.

NOW, THEREFORE, the Plan is hereby amended effective as of January 1, 2009, as follows:

I.

The following is added as a new
Section 2.12 of Article II of the Plan:

2.12 Separation from Service shall mean to the extent necessary to comply with
Section 409A of the Internal Revenue Code, references to termination of employment, separation from service or variations thereof in the Plan as applied to the Tier 2 SIP benefits described in Article IV shall mean the
Employees separation from service from the PBS&J Controlled Group within the meaning of Section 409A(a)(2)(A)(i) of the Code and the rules of Treasury Regulations Section 1.409A-1(h); provided that less
than 50% is adopted in lieu of the default 20% or less standard for determining a separation from service. The PBS&J Controlled Group means the Corporation and every entity or other person which collectively
with the Corporation constitutes a single service recipient (as that term is defined in Treasury Regulations Sections 1.409A-1(g)) as the result of the application of the rules of Treasury Regulations Sections 1.409A-1(h)(3).

II.

Section 4.2 of Article IV
of the Plan shall be replaced with the following:

4.2 A Participant shall be deemed disabled if he meets the definition of
disability as set forth in Section 1.409A-3(i)(4) of the Treasury regulations.



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III.

The following is hereby added as new Sections 5.3 and 5.4 of Article V of the Plan:



|    |  |     |  |                                                                                                                                                                                                                                                                                 
|--- |  | --- |  | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|5.3 |  | (A) |  | Benefits for Participants that were (i) employed on September 30, 2008 and (ii) eligible under the Plan for non-stock benefits have been converted to the Key Employee Capital
Accumulation Plan and will be provided in accordance with the requirements of that plan document.
|    |  |    
|    |  | (B) |  | For Participants who terminated employment prior to September 30, 2008, any non-stock benefits shall be paid in accordance with this Plan.                                                                                                                                      

5.4 The annual non-stock benefits that are in pay status as of December 31, 2008 shall
continue to be paid in accordance with the current payment schedule. Such payment terms may not be changed. To the extent that payment has not yet commenced, the non-stock benefits shall be paid in monthly installments for a period of 10 years
commencing on the date that is 30 days following the Participants Separation from Service (including death) or in the case of a Disability Benefit described in Section 5.2 of the Plan, the date set forth therein.

IV.

The following is hereby added as
a new Section 8.12 of Article VIII of the Plan:

8.12 Section 409A Compliance. The Company intends for this Plan to conform in all
respects to the requirements under Section 409A of the Code, the failure of which would result in the imposition or accrual of penalties, interest or additional taxes under Section 409A of the Code (the Section 409A
Requirements). Accordingly, the Company intends for this Plan to be interpreted, construed, administered and applied in a manner as shall meet and comply with the Section 409A Requirements, and in the event of any inconsistency
between this Plan and the Section 409A Requirements, this Plan shall be reformed so as to meet the Section 409A Requirements. Any reference in this Plan to Section 409A of the Code, or any subsection thereof, shall be deemed to mean
and include, to the extent then applicable and then in force and effect (but not to the extent overruled, limited or superseded), published rulings, notices and similar announcements issued by the Internal Revenue Service under or interpreting
Section 409A of the Code and regulations (proposed, temporary or final) issued by the Secretary of the Treasury under or interpreting Section 409A of the Code.

IN WITNESS WHEREOF, this Amendment has been executed as of this 31stday of December, 2008.



THE PBSJ CORPORATIONBy:

/s/ Donald J. VranaTitle:

SVP and CFOCORPORATION




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