The invention relates to a process for the preparation of a propylene homopolymer or a propylene α-olefin random copolymer comprising the step of a) preparing a propylene homopolymer or a propylene α-olefin random copolymer, wherein the α-olefin is chosen from the group consisting of ethylene, and α-olefins having 4 to 10 carbon atoms, for example 1-butene or 1-hexene by contacting at least the propylene and optionally α-olefin, with a catalyst in a gas-phase reactor at a temperature T1 and a pressure P1, wherein T1 is chosen in the range from 75 to 90° C., for example in the range from 77 to 85° C., for example in the range from 78 to 83° C., wherein P1 is chosen in the range from 22 to 30 bar to prepare a propylene homopolymer (A′) or a propylene α-olefin random copolymer (A′).