WESTPORT FUEL SYSTEMS INC.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 20-F

(Mark One)

OR

For the Fiscal Year Ended December 31, 2025

OR

For the transition period from January 31, 2023 to December 31, 2025

OR

Date of event requiring this shell company report December 31, 2025

Commission file number 001-34152

WESTPORT FUEL SYSTEMS INC.

(Exact name of registrant as specified in its charter)

Not applicable

(Translation of Registrant's name into English)

Alberta, Canada

(Jurisdiction of incorporation or organization)

1691 West 75th Avenue, V6P 6P2,

(Address of principal executive offices)

Daniel Sceli, (1)(604) 718-2046, invest@westport.com,

1691 West 75th Avenue, V6P 6P2, Vancouver, Canada

(Name, Telephone, E-mail and/or Facsimile number and Address of Company Contact Person)

Securities registered pursuant to Section 12(b) of the Act:

Securities registered or to be registered pursuant to Section 12(g) of the Act. None.

Securities for which there is a reporting obligation pursuant to Section 15(d) of the Act. None.

Indicate the number of outstanding shares of each of the issuer’s classes of capital or common stock as of the close of the period covered by the annual report.

17,375,213 Common shares, no par value

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.

Yeso No x

If this report is an annual or transition report, indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934.

Yeso No x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.

Yes x Noo

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).

Yes x Noo

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or an emerging growth company. See definition of “large accelerated filer,"accelerated filer,” and "emerging growth company" in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.

o

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report.

x

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements.

o

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b).

o

Indicate by check mark which basis of accounting the registrant has used to prepare the financial statements included in this filing:

If “Other” has been checked in response to the previous question, indicate by check mark which financial statement item the registrant has elected to follow.

o Item 17 o Item 18

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act).

Yeso Nox

Table of Contents

Cautionary Note Regarding Forward-Looking Statements

Certain statements contained in this annual report constitute “forward-looking statements” within the meaning of the United States Private Securities Litigation Reform Act of 1995, as amended (collectively referred to as, “forward-looking statements”). When used, the words “may”, “would”, “could”, “will”, “intend”, “plan”, “anticipate”, “believe”, “estimate”, “expect”, “project” and similar expressions, as they relate to us or our management, are intended to identify forward-looking statements. In particular, this annual report contains forward-looking statements which include, statements relating to our objectives, plans and strategies, statements that contain projections of results of operations or of financial condition and all statements (other than statements of historical facts) that address activities, events or developments that we intend, expect, project, believe or anticipate will or may occur in the future.

Such statements reflect our current views with respect to future events and are subject to certain risks, uncertainties and assumptions. Actual results may differ materially from those expressed in these forward-looking statements due to several uncertainties and risks, including the risks described in this prospectus supplement, the prospectus and the documents incorporated by reference herein and therein and other unforeseen risks. Such risks, uncertainties, factors and assumptions include, without limitation:

•supply of, demand for and price of lower/zero emission propulsion systems for transportation;

•actions of government and governmental authorities, including, without limitation, the imposition of tariffs, implementation of emission and fuel consumption standards, the implementation of policies or other measures that promote the supply of and demand for liquified natural gas, renewable natural gas and hydrogen;

•conditions in the hydrogen and other industries, including fluctuations in the supply, demand and price for hydrogen, including demand for hydrogen in transportation and the implementation of hydrogen fueling infrastructure;

•market acceptance of our products;

•the ability to raise additional capital or earn enough revenue to fund operations as a going concern;

•product development delays and delays in contractual commitments;

•changing environmental legislation and regulations;

•the ability to attract and retain business partners;

•the success of our joint ventures;

•the success of our business partners and original equipment manufacturers (“OEMs”) with whom we partner;

•future levels of government funding and incentives;

•competition from other technologies;

•price differential between compressed natural gas, liquid natural gas, liquid petroleum gas and hydrogen relative to petroleum-based fuels;

•limitations on our ability to protect our intellectual property;

•various events that could disrupt operations, including cybersecurity attacks;

•potential claims or disputes in respect of our intellectual property;

•limitations in our ability to successfully integrate acquired businesses;

•limitations in the development of natural gas and hydrogen refueling infrastructure;

•the ability to provide and access the capital required for research, product development, operations and marketing;

•there could be unforeseen claims made against us;

•our international business operations could expose us to regulatory risks or factors beyond our control such as currency exchange rates, changes in governmental policy, including without limitation, those relating to the regulation of rates, tariffs, import/exports, taxes, wages, labour and immigration, trade barriers, trade embargoes, investigation of sanctions relating to corruption of foreign public officials or international sanctions and delays in the development of international markets for our products;

•volatility in the price of our Common Shares on the TSX and Nasdaq;

•other risks relating to our Common Shares and debt securities;

•the consequences to U.S. investors if we are treated as a passive foreign investment company;

•the risks of operating in China;

•risk of conflict related to our directors and officers who may currently, or in the future, also serve as directors and/or officers of other public companies that may be involved in the same industry as us; and

•those other risks discussed in Item 3D “Key Information – Risk Factors” as well as in other portions of this annual report.

Readers are cautioned that forward-looking statements are not based on historical facts but instead are based on reasonable assumptions, estimates, analysis and opinions of our management at the time they were provided or made, in light of its experience and its perception of trends, current conditions and expected developments, as well as other factors that management believes to be relevant and reasonable in the circumstances, and involve known and unknown risks, uncertainties and other factors which may cause our actual results, performance or achievements, as applicable, to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements.

Readers are cautioned that the foregoing lists are not exhaustive of all factors and assumptions that may have been used. Although we have attempted to identify important factors that could cause actual results to differ materially, there may be other factors that cause results not to be as anticipated, estimated or intended. There can be no assurance that such forward-looking statements will prove to be accurate as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking statements. The forward-looking statements contained in this prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein and therein are presented for the purposes of assisting readers in understanding our expected financial and operating performance and our plans and objectives and may not be appropriate for other purposes.

Any forward-looking statement is made only as of this annual report, unless otherwise indicated, and represent the views and expectations of our management. We undertake no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as otherwise required by applicable law.