Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first user equipment (UE) may identify a collision on a victim resource based at least in part on an aggressor reservation transmitted by a second UE. The first UE may transmit, to the second UE via a sidelink feedback channel, a resource collision indication that indicates at least one of the victim resource or the aggressor reservation, wherein the resource collision indication is multiplexed on one or more resources that are useable for sidelink feedback. Numerous other aspects are provided.