On January 30, 2009, the Board of Directors (the “Board”) of Donaldson Company, Inc. (the “Company”) adopted amendments, effective as of that date, to the Company’s Amended and Restated Bylaws (the “Bylaws”).

The amendments to Section 3 of the Bylaws provide that additional information must be set out in a stockholder’s notice to the Secretary with respect to a nomination for election to the Board of Directors and a stockholder proposal of business at an annual meeting of stockholders. The amended Bylaws provide that the stockholder must, in addition to the information that was previously required, provide the following information with respect to the stockholder and any Stockholder Associated Person (as defined in the amended Bylaws): (i) the nominee holder for and number of shares owned beneficially by such person; (ii) whether and the extent to which any hedging or other transaction has been entered into by or on behalf of, or any other agreement, arrangement or understanding has been made, the effect or intent of which is to mitigate loss to or manage risk or benefit of share price changes for, or to increase or decrease the voting power of, such person with respect to any share of stock of the Company; (iii) to the extent known by the stockholder giving the notice, the name and address of any other stockholder supporting the proposal of business or the nominee for election on the date of such stockholder’s notice; (iv) a description of all agreements, arrangements or understandings between or among such persons or any other person in connection with the proposal of such business or nomination by such stockholder; (v) with respect to stockholder nominees for election to the Board of Directors, any relationship between or among the stockholder giving notice and any Stockholder Associated Person, on the one hand, and each proposed nominee on the other hand and (vi) notice whether such persons intend to solicit proxies in connection with the proposed business or nomination by such stockholder.

The amendments to Section 3 of the Bylaws also provide that meetings of stockholders may be adjourned by the chairman of the meeting whether or not a quorum is present.

The amendments to Section 4 of the Bylaws provide that the number of directors which constitute the Board shall be the number, not less than three nor more than fifteen, as may be determined by the Board by a vote of not less than a majority of the directors then in office and that stockholders do not have the right to determine such number. The amendments to Section 4 of the Bylaws also remove stock ownership and age requirements for directors.

The amendments to Section 26 of the Bylaws provide that the Company is not obligated to indemnify individuals found to be liable to the Company unless the court which found such individual liable determines upon application that, despite the adjudication of liability but in view of all the circumstances of the case, such person is fairly and reasonably entitled to indemnity.

Other amendments to the Bylaws are immaterial language changes and clarifying or conforming changes. The foregoing summary of changes to the Bylaws is qualified in its entirety by the full text of the Amended and Restated Bylaws of the Company, as amended, a copy of which is attached hereto as Exhibit 3.1 and incorporated herein by reference.