WESTPORT FUEL SYSTEMS INC. 320 Bay Street, 14th Floor Toronto, ON M5H 4A6 www.computershare.com Security Class Holder Account Number Voting Instruction Form ("VIF") - Annual General and Special Meeting to be held on June 30, 2026 NON-REGISTERED (BENEFICIAL) SECURITYHOLDERS 1. We are sending to you the enclosed proxy-related materials that relate to a meeting of the holders of the series or class of securities that are held on your behalf by the intermediary identified above. Unless you attend the meeting and vote in person, your securities can be voted only by management, as proxy holder of the registered holder, in accordance with your instructions. 2. We are prohibited from voting these securities on any of the matters to be acted upon at the meeting without your specific voting instructions. In order for these securities to be voted at the meeting, it will be necessary for us to have your specific voting instructions. Please complete and return the information requested in this VIF to provide your voting instructions to us promptly. 3. If you want to attend the meeting and vote in person, please write your name in the place provided for that purpose in this form. You can also write the name of someone else whom you wish to attend the meeting and vote on your behalf. Unless prohibited by law, the person whose name is written in the space provided will have full authority to present matters to the meeting and vote on all matters that are presented at the meeting, even if those matters are not set out in this form or the information circular. Consult a legal advisor if you wish to modify the authority of that person in any way. If you require help, please contact the Registered Representative who services your account. 4. This VIF should be signed by you in the exact manner as your name appears on the VIF. If these voting instructions are given on behalf of a body corporate set out the full legal name of the body corporate, the name and position of the person giving voting instructions on behalf of the body corporate and the address for service of the body corporate. 5. If a date is not inserted in the space provided on the reverse of this VIF, it will be deemed to bear the date on which it was mailed by management to you. 6. When properly signed and delivered, securities represented by this VIF will be voted as directed by you, however, if such a direction is not made in respect of any matter, and the VIF appoints the Management Nominees, the VIF will direct the voting of the securities to be made as recommended in the documentation provided by Management for the meeting. 7. Unless prohibited by law, this VIF confers discretionary authority on the appointee to vote as the appointee sees fit in respect of amendments or variations to matters identified in the notice of meeting or other matters as may properly come before the meeting or any adjournment thereof. 8. By providing voting instructions as requested, you are acknowledging that you are the beneficial owner of, and are entitled to instruct us with respect to the voting of, these securities. 9. If you have any questions regarding the enclosed documents, please contact the Registered Representative who services your account. 10. This VIF should be read in conjunction with the information circular and other proxy materials provided by Management. VIFs submitted must be received by 10:00 am, PDT, on June 26, 2026. VOTE USING THE TELEPHONE OR INTERNET 24 HOURS A DAY 7 DAYS A WEEK! To Vote Using the Telephone • Call the number listed BELOW from a touch tone telephone. 1-866-734-VOTE (8683) Toll Free To Vote Using the Internet • Go to the following web site: www.investorvote.com • Smartphone? Scan the QR code to vote now. To Virtually Attend the Meeting • You can attend the meeting virtually by visiting the URL provided on the back of this document. If you vote by telephone or the Internet, DO NOT mail back this VIF. Voting by mail may be the only method for securities held in the name of a corporation or securities being voted on behalf of another individual. Voting by mail or by Internet are the only methods by which a holder may choose an appointee other than the Management appointees named on the reverse of this VIF. Instead of mailing this VIF, you may choose one of the two voting methods outlined above to vote this VIF. To vote by telephone or the Internet, you will need to provide your CONTROL NUMBER listed below. CONTROL NUMBER ------- Fold ------- Fold

------- Fold ------- Fold Appointee(s) I/We being holder(s) of securities of Westport Fuel Systems Inc. (the “Corporation”) hereby appoint: Daniel Sceli, Chief Executive Officer, or failing this person, Larry Kyle, Vice President, Legal and Intellectual Property and Corporate Secretary (the "Management Nominees") OR If you wish to attend in person or appoint someone else to attend on your behalf, print your name or the name of your appointee in this space (see Note #3 on reverse). Note: If completing the appointment box above YOU MUST go to http://www.computershare.com/WestportFuel and provide Computershare with the name and email address of the person you are appointing. Computershare will use this information ONLY to provide the appointee with an Invite Code to gain entry to the online meeting. as my/our proxyholder with full power of substitution and to attend, act and to vote for and on behalf of the voter in accordance with the following direction (or if no directions have been given, as the proxyholder sees fit) and on all other matters that may properly come before the Annual General and Special Meeting of shareholders of the Corporation to be held online at https://meetnow.global/MPUGFX4 on June 30, 2026 at 10:00 am, PST, and at any adjournment or postponement thereof. VOTING RECOMMENDATIONS ARE INDICATED BY HIGHLIGHTED TEXT OVER THE BOXES. 1. Election of Directors 01. Michele J. Buchignani For Withhold 02. Anthony Guglielmin For Withhold 03. Bradley Kotush For Withhold 04. Daniel Sceli 05. Karl-Viktor Schaller 06. Eileen Wheatman 2. Appointment of Auditors Appointment of Deloitte LLP as Auditors of the Corporation for the ensuing year and authorizing the Directors to fix their remuneration. For Withhold 3. Advisory Vote to Approve our Named Executive Officer Compensation RESOLVED, on an advisory basis and not to diminish the role and responsibilities of the Board of Directors of the Corporation, that the shareholders accept the approach to executive compensation disclosed in the Corporation’s Management Information Circular dated effective May 12, 2026. For Against 4. Special Resolution Approving Change of Corporation Name To consider and, if thought advisable, to pass the Name Change Resolution, the full text of which is set forth in the Management Information Circular effective May 12, 2026, to change the name of Westport Fuel Systems Inc. For Against Authorized Signature(s) – This section must be completed for your instructions to be executed. I/We authorize you to act in accordance with my/our instructions set out above. I/We hereby revoke any VIF previously given with respect to the Meeting. If no voting instructions are indicated above, and the VIF appoints the Management Nominees, this VIF will be voted as recommended by Management. If you are voting on behalf of a corporation you are required to provide your name and designation of office, e.g., ABC Inc. per John Smith, President. Signature(s) Date Signing Capacity Interim Financial Statements - Mark this box if you would like to receive Interim Financial Statements and accompanying Management’s Discussion and Analysis by mail. Annual Financial Statements - Mark this box if you would like to receive the Annual Financial Statements and accompanying Management’s Discussion and Analysis by mail. If you are not mailing back your VIF, you may register online to receive the above financial report(s) by mail at www.computershare.com/mailinglist. 3 8 5 9 1 5 A R 1W P T Q

WESTPORT FUEL SYSTEMS INC. 6-K