Popper’s critical rationalism and especially his solution of the problem of induction, which is based on the fact that beliefs are not inferences and rejection is not induc-tive, has little orthodox followers but more critics and revisers. Many of Popper’s fol¬lowers admit that his concept is rightly criticized from various positions and they seek to further develop Popper’s legacy by adopting diﬀerent strategies and correc¬tions. Unlike the orthodox followers of Popper (e.g. David Miller) they tend to make serious changes to Popper’s conception (e.g. John Watkins, John Worrall) under the inﬂuence of Imre Lakatos and his discussions with Popper. Donald Gillies belongs to the seemingly moderate revisers of Popper’s legacy. He tries to deal with the objec¬tions raised, especially against falsiﬁcationism, and he calls his elaborate conception modiﬁed falsiﬁcationism. This article deals with the question as to what extent Gillies’ attempt is successful and how it responds to the real problems of falsiﬁcationism within contemporary debates.