Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive first configuration information indicating a first guard interval associated with sidelink communications. The UE may transmit, to a base station and another UE, a first sidelink communication using the first guard interval. The UE may transmit, to the base station and using a second guard interval having a second length that is different from a first length of the first guard interval, an uplink communication. Numerous other aspects are described.