UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549



FORM 40-F/A

(Amendment No. 1)



|o  | REGISTRATION STATEMENT PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934   
|-- | ---------------------------------------------------------------------------------------
|   |                                                                                        
|OR
|  
|x  | ANNUAL REPORT PURSUANT TO SECTION 13(a) OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934



For the fiscal year ended December 31, 2013



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Commission file number: 001-34152







WESTPORT INNOVATIONS INC.

(Exact Name of Registrant as Specified in its
charter)



|Alberta                                                          |  | 3537                                                                    |  | N/A                                                    
|---------------------------------------------------------------- |  | ----------------------------------------------------------------------- |  | -------------------------------------------------------
|(Province or other jurisdiction ofincorporation or organization) |  | (Primary Standard Industrial ClassificationCode Number (if applicable)) |  | (I.R.S. Employer Identification Number (if applicable))



1750 West 75thAvenue, Suite 101

Vancouver, British Columbia, Canada V6P 6G2

(604) 718-2000

(Address and telephone number of Registrant’s
principal executive offices)



|C T Corporation System
        111 Eighth Avenue
        New York, NY 10011
        (212) 590-9070                       |  | Copies to:
        Gordon Caplan
        Willkie Farr & Gallagher LLP
        787 Seventh Avenue
        New York, New York 10019
        (212) 728-8266
|------------------------------------------------------------------------------------------------------------------------ |  | --------------------------------------------------------------------------------------------------------------------------------------------------------
|(Name, address (including zip code) and telephone number (includingarea code) of agent for service in the United States) | 



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











|Title of Each Class:        |  | Name of Each Exchange On Which Registered:
|--------------------------- |  | ------------------------------------------
|Common Shares, no par value |  | NASDAQ Global Select Market               



Securities registered or to be registered pursuant to Section 12(g)
of the Act: N/A



Securities for which there is a reporting obligation pursuant to
Section 15(d) of the Act: N/A



For annual reports, indicate by check mark the information filed
with this form:



| | oAnnual Information Form |  | xAudited Annual Financial Statements
| | ------------------------ |  | ------------------------------------



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: As at December 31, 2013, 62,733,762common shares of the Registrant were issued and outstanding.



Indicate by check mark whether the Registrant (1) has filed all
reports required to be filed by Section 13 or 15(d) of the Exchange Act 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.
x Yes o No



Indicate by check mark whether the registrant has submitted electronically
and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted 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 and post such files). x Yes o
No


















EXPLANATORY NOTE



Westport Innovations Inc. (the “Company” or the
“Registrant”) is a Canadian issuer eligible to file its annual report pursuant to Section 13 of the Securities
Exchange Act of 1934, as amended (the “Exchange Act”), on Form 40-F pursuant to the multi-jurisdictional disclosure
system of the Exchange Act. The Company is a “foreign private issuer” as defined in Rule 3b-4 under the Exchange Act.
Equity securities of the Company are accordingly exempt from Sections 14(a), 14(b), 14(c), 14(f) and 16 of the Exchange Act pursuant
to Rule 3a12-3.



This Amendment No. 1 (“Amendment No. 1”) to the
Company’s Annual Report on Form 40-F for the year ended December 31, 2013 originally filed on February 27, 2014 with the
Securities and Exchange Commission (“SEC”) in the United States (the “Original Form 40-F”)
is being filed specifically to furnish the audited financial statements of Cummins Westport Inc. and notes thereto as at and for
the years ended December 31, 2013 and December 31, 2012 together with the report of the independent auditors thereon.



Except as set forth above, this Amendment No. 1 does not modify
or update the disclosure in the Original Form 40-F and, therefore, it is not included herein.  Except as may be specifically
indicated herein, the Original Form 40-F continues to describe conditions as of the date of the Original Form 40-F and the Company
has not modified or updated other disclosures presented in the Original Form 40-F.  This Amendment No. 1 does not reflect
events occurring after the date of the Original Form 40-F nor does it modify or update disclosures affected by subsequent events. 
Accordingly, this Amendment No. 1 should be read in conjunction with the Original Form 40-F.





FORWARD-LOOKING STATEMENTS



This amended annual report on Form 40-F/A and the exhibits
attached hereto contain forward-looking statements or information within the meaning of the United States Private Securities Litigation
Reform Act of 1995. When used in this amended annual report on Form 40-F/A, the words “may”, “would”, “could”,
“will”, “intend”, “plan”, “anticipate”, “believe”, “estimate”,
“expect”, “project” and similar expressions, as they relate to the Company or the Company’s management,
are intended to identify forward-looking statements. In particular, this amended annual report on Form 40-F/A and the documents
incorporated by reference herein contain forward-looking statements pertaining to the following:

| | • | the future demand for Cummins Westport Inc. (“CWI”) products and Company products;
| | - | ----------------------------------------------------------------------------------

| | • | increasing penetration within our existing markets and expansion of those markets geographically;
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| | • | continuing growth in the transportation sector and in the natural gas engine market;
| | - | ------------------------------------------------------------------------------------

| | • | the timing of and our ability to successfully launch new technology initiatives, including in light-, medium-, and heavy-duty
markets;
| | - | --------------------------------------------------------------------------------------------------------------------------------------

| | • | our ability to exploit and protect our intellectual property;
| | - | -------------------------------------------------------------

| | • | our capital expenditure and investment programs;
| | - | ------------------------------------------------

| | • | the future desirability and use of natural gas as an alternative fuel;
| | - | ----------------------------------------------------------------------

| | • | commodity prices and the fuel price differential between natural gas and diesel;
| | - | --------------------------------------------------------------------------------

| | • | ongoing relationships between us and our business and partners and the results of our development programs with such partners;
| | - | ------------------------------------------------------------------------------------------------------------------------------

| | • | our ability to continue to compete with our competitors and their technologies;
| | - | -------------------------------------------------------------------------------

| | • | the capital and operating costs of vehicles using our technologies relative to alternative technologies;
| | - | --------------------------------------------------------------------------------------------------------







| | • | profit margins and production costs of engines incorporating our technologies;
| | - | ------------------------------------------------------------------------------

| | • | the further development of infrastructure supporting the application of natural gas as an alternative fuel;
| | - | -----------------------------------------------------------------------------------------------------------

| | • | increasingly stringent environmental and emissions regulations in the future;
| | - | -----------------------------------------------------------------------------

| | • | ongoing availability of government incentives and mandates for our technology;
| | - | ------------------------------------------------------------------------------

| | • | our ability to attract and retain employees;
| | - | --------------------------------------------

| | • | demand for engines incorporating our technologies;
| | - | --------------------------------------------------

| | • | the timing of commissioning of liquefied natural gas (“LNG”) refueling stations;
| | - | --------------------------------------------------------------------------------

| | • | production capacity methods for our methods for our LNG system;
| | - | ---------------------------------------------------------------

| | • | increasing commercialization of our technologies;
| | - | -------------------------------------------------

| | • | expansion of our product offerings and markets;
| | - | -----------------------------------------------

| | • | our estimates and assumptions used in our accounting policies, and accruals, including warranty accruals, and financial condition;
| | - | ----------------------------------------------------------------------------------------------------------------------------------

| | • | our adoption, timing and ability to meet certain accounting standards;
| | - | ----------------------------------------------------------------------

| | • | the ability of our products to adapt to the use of biogas, renewable natural gas and manufactured fuels, including hydrogen,
as fuels;
| | - | --------------------------------------------------------------------------------------------------------------------------------------

| | • | our compliance with environmental regulations; and
| | - | --------------------------------------------------

| | • | the alignment of our business segments.
| | - | ---------------------------------------

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 a number of uncertainties and risks, including the risks described in this
amended annual report on Form 40-F/A and in the documents incorporated by reference herein and other unforeseen risks, including,
without limitation:

| | • | market acceptance of our products;
| | - | ----------------------------------

| | • | product development delays and delays in contractual commitments;
| | - | -----------------------------------------------------------------

| | • | changing environmental regulations;
| | - | -----------------------------------

| | • | the ability to attract and retain business partners;
| | - | ----------------------------------------------------

| | • | 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 (“CNG”), LNG and liquefied petroleum gas (“LPG”)
relative to petroleum-based fuels;
| | - | -------------------------------------------------------------------------------------------------------------------------------------







| | • | limitations on our ability to protect our intellectual property;
| | - | ----------------------------------------------------------------

| | • | 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 refueling infrastructure;
| | - | -----------------------------------------------------------------------

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

| | • | unforeseen claims made against us;
| | - | ----------------------------------

| | • | exposure to factors beyond our control through our international business operations, such as currency exchange rates, changes
in governmental policy, trade barriers, trade embargoes and delays in the development of international markets for our products;
and
| | - | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | • | those risks discussed under the heading “Risk Factors” in the Annual Information Form (“AIF”)
of the Company filed as Exhibit 99.1 to the Original Form 40-F.
| | - | -------------------------------------------------------------------------------------------------------------------------------------------------------------

You should not rely on any forward-looking statements. We undertake
no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise,
after the date of this annual report on Form 40-F, except as otherwise required by law.



UNDERTAKING



The Company undertakes to make available, in person or by telephone,
representatives to respond to inquiries made by the SEC’s staff, and to furnish promptly, when requested to do so by the
SEC staff, information relating to: the securities registered pursuant to Form 40-F; the securities in relation to which the obligation
to file an annual report on Form 40-F arises; or transactions in said securities.



CONSENT TO SERVICE OF PROCESS



The Company previously filed an Appointment of Agent for Service
of Process and Undertaking on Form F-X with the SEC on July 22, 2008, with respect to the class of securities in relation to which
the obligation to file this amended annual report on Form 40-F/A arises.









EXHIBIT INDEX



The following exhibits have been filed as part of this annual report:



|Exhibit            |  | Description                                                                                                                                                                                                                                
|------------------ |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|                   |  |                                                                                                                                                                                                                                            
|Annual Information
|99.1*              |  | Annual Information Form of the Company for the year ended December 31, 2013                                                                                                                                                                
|                   |  |                                                                                                                                                                                                                                            
|99.2*              |  | Audited consolidated financial statements of the Company and notes thereto for the years ended December 31, 2013 and December 31, 2012 and nine months ended December 31, 2011 together with the report of the independent auditors thereon
|                   |  |                                                                                                                                                                                                                                            
|99.3*              |  | Management’s Discussion and Analysis for the year ended December 31, 2013                                                                                                                                                                  
|99.4               |  | Audited financial statements of Cummins Westport Inc. and notes
        thereto as at and for the years ended December 31, 2013 and December 31, 2012 together with the report of the independent auditors
        thereon                 
|                   |  |                                                                                                                                                                                                                                            
|Certifications    
|99.5               |  | Certificate of Chief Executive Officer Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002                                                                                                                                           
|                   |  |                                                                                                                                                                                                                                            
|                   |  |                                                                                                                                                                                                                                            
|99.6               |  | Certificate of Chief Financial Officer Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002                                                                                                                                           
|                   |  |                                                                                                                                                                                                                                            
|                   |  |                                                                                                                                                                                                                                            
|99.7               |  | Certificate of Chief Executive Officer Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002                                                                                            
|                   |  |                                                                                                                                                                                                                                            
|99.8               |  | Certificate of Chief Financial Officer Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002                                                                                            
|                   |  |                                                                                                                                                                                                                                            
|Consents          
|99.9*              |  | Consent of KPMG LLP regarding the financial statements of the Company                                                                                                                                                                      
|                   |  |                                                                                                                                                                                                                                            
|                   |  |                                                                                                                                                                                                                                            
|99.10              |  | Consent of KPMG LLP regarding the financial statements of Cummins Westport Inc.                                                                                                                                                            
|Exhibits           |  |                                                                                                                                                                                                                                            
|101.1*             |  | XBRL Interactive Data File                                                                                                                                                                                                                 



| | * | Previously filed with our Annual Report on Form 40-F as filed
with the Securities and Exchange Commission on February 27, 2014
| | - | ------------------------------------------------------------------------------------------------------------------------------











SIGNATURES



Pursuant to the requirements of the Exchange
Act, the Registrant certifies that it meets all of the requirements for filing on Form 40-F/A and has duly caused this annual report
to be signed on its behalf by the undersigned, thereto duly authorized.





| | WESTPORT INNOVATIONS INC.
| | -------------------------
| |                          
| |                          
| | By:                      
| | Name:                    
| | Title:                   



Date: March 27, 2014