The invention provides a process for converting a paraffinic feedstock comprising at least 50 wt % of compounds boiling above 370° C., a paraffin content of at least 60 wt %, an aromatics content below 1 wt %, a naphthenic content below 2 wt %, a nitrogen content below 0.1 wt %, and a sulphur content below 0.1 wt %, comprising: (a) reacting the feedstock with hydrogen at a temperature between 175 and 400° C. and a pressure between 20 and 100 bar using a catalyst comprising 0.005 to 5.0 wt % of a Group VIII noble metal on a carrier comprising 0.1-15 wt % zeolite beta and at least 40 wt % amorphous silica-alumina (b) withdrawing the effluent (c) subjecting the effluent to a fractionation step to form a heavy fraction, an intermediate fraction, and a light fraction; and (d) providing at least part of the heavy fraction to the reaction zone.