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                                   EXHIBIT 4.2

                       FIRST AMENDMENT TO BROOKTROUT, INC.

                            1999 STOCK INCENTIVE PLAN

         This First Amendment (the "First Amendment") to the Brooktrout, Inc.
("Brooktrout" or the "Company") 1999 Stock Incentive Plan, dated December 8,
1999 (the "Plan"), was adopted by the Board of Directors (the "Board") of the
Company on December 8, 1999.

         WHEREAS, the Board believes that the availability of an adequate number
of shares of common stock, $.01 par value per share (the "Stock"), under the
Plan has been, and in the future will be, an important factor in attracting and
retaining the highest caliber directors, executives and employees of the
Company;

         WHEREAS, the Board further believes that the number of shares of Stock,
available for issuance under the Plan is currently insufficient; and

         WHEREAS, the Board adopted an increase of six hundred fifty thousand
(650,000) shares of Stock available for issuance under the Plan;

         NOW, THEREFORE, the Plan is hereby amended in the following manner: The
first sentence of Section 3 clause (a) is amended to increase the maximum number
of shares of Stock reserved and available for issuance under the Plan from two
hundred fifty thousand (250,000) to nine hundred thousand (900,000).