EXHIBIT 5 November 25, 1997 Interface Systems, Inc. 5855 Interface Drive Ann Arbor, Michigan 48103 Ladies and Gentlemen: We have served as counsel to Interface Systems, Inc. (the "Company") in connection with the preparation of the Registration Statement (Form S-8) to be filed by the Company on November 25, 1997 with the Securities and Exchange Commission under the Securities Act of 1933, as amended, representing the issuance in the manner described in the Registration Statement of 225,000 shares of the Company's Common Stock, $.10 par value (the "Common Stock"), pursuant to the Interface Systems, Inc. Employee Stock Purchase Plan. We have examined and relied upon the originals, or copies certified or otherwise identified to our satisfaction, of such corporate records, documents, certificates and other instruments as in our judgment are necessary or appropriate to enable us to render the opinion expressed below. Based upon such examination and our participation in the preparation of the Registration Statement, it is our opinion that (1) the Company is duly incorporated and validly existing as a corporation in good standing under the laws of Delaware and (2) the Common Stock, when issued in the manner described in the Registration Statement, will be validly issued, fully paid and nonassessable. We consent to the filing of this opinion as Exhibit 5 to the Registration Statement. Very truly yours, DYKEMA GOSSETT PLLC /s/ Marguerite M. Gritenas Marguerite M. Gritenas (313) 568-6503