There is provided mechanisms for determining time-of-arrival of a PRACH preamble. A method is performed by a radio access network node. The radio access network node is configured for beamformed communication in a set of beams. The method comprises receiving, from a UE and at a TRP of the radio access network node, a PRACH preamble. The method comprises determining a weight factor value for the PRACH preamble. The weight factor value is dependent on beam information mapped to the PRACH preamble. The beam information identifies one of the beams in the set of beams. The method comprises determining time-of-arrival of the PRACH preamble using hypothesis testing that incorporates the weight factor value.