Summary This paper presents an immanent criticism of Lakatos' reconstruction of the degenerating phase of Bohr's atomic theory. That is to say, the historiographical methods used are exclusively of a Lakatosian kind. Such a closer Lakatosian look at the historical episode in question shows that Lakatos' own reconstruction is incorrect on three essential points. These are the role of the correspondence principle, the position of the hard core in Bohr's programme, and the presence of important novel predicted facts. I conclude (...) that these defects are irreparable within the framework of Lakatos' methodology of scientific research programmes. (shrink)