This paper is concerned with the denunciation of declarations of acceptance of the compulsory jurisdiction of the International Court of Justice under the Optional Clause and the impact that the 1984 Judgment of the Court in the jurisdictional phase of the Nicaragua case may have had upon it. In this decision the Court found that the principle of good faith is of paramount importance in the legal regime of the Optional Clause and introduced in that regime the element of a ‘reasonable time’ for the denunciation of declarations of indefinite duration and silent as to termination. The relevant passage of the Judgment is discussed with a view to determine the contours of this requirement and the ways it may operate in practice.