The invention provides a method for the production of a composite comprising microfibrillated cellulose (MFC) and precipitated calcium carbonate. The method is characterized in that MFC is added to a suspension of calcium hydroxide during carbonation, whereby calcium carbonate is precipitated onto fibers or fibrils of the MFC in a controlled manner. By adding microfibrillated cellulose to the calcium suspension during the carbonation, the brightness and the strength of the MFC/PCC-composite is enhanced. Moreover, the inventive method facilitates the distribution of calcium dioxide and MFC in the suspension and thus gives rise to a more homogenous product.