Apparatuses, methods, and systems are disclosed for preempting an uplink resource allocation. One apparatus includes a processor and a transceiver that receives a first allocation of uplink resources in a mobile communication network and receives a second allocation of uplink resources. Here, the second allocation at least partially overlaps in time with the first allocation and the second allocation is received at a later time than the first allocation. The processor determines whether the second allocation is associated with higher priority traffic than the first allocation and preempts the first allocation to generate a TB according to the second allocation in response to the second allocation being associated with higher priority traffic than the first allocation.