Aspects of the present disclosure relate to techniques that may help enable the determination of uplink resource allocation in systems that support dynamic uplink-downlink subframe configurations. An example method generally includes receiving signaling indicating a dynamic uplink-downlink (UL-DL) subframe configuration, determining hybrid automatic repeat request (HARQ) acknowledgment/negative acknowledgment (ACK/NACK) timing based on a reference UL-DL subframe configuration, and determining HARQ resource allocation based on the dynamic UL-DL subframe configuration.