A growing body of interdisciplinary scholarship addresses the issue of global constitutionalism. Scholarly contributions analyze the allocation of power within rule-systems of international law, how it affects subsequent international practice and its connection with political institutions. This article questions the validity of the use of constitutional concepts as a means for interpreting international law. An argument is made that current contributions on international constitutionalism are grounded on unstated assumptions. It is maintained that in order to restore coherence and unity within the international legal system, interpretations of international law should be carried out through interpretive means that are specifically conceived for international law. This article shows that although constitutionalism may be featured as an autonomous concept of international law, it is not able to restore coherence and unity within the international legal system. Therefore, it cannot be regarded as a remedy to the phenomenon of fragmentation.