Certain aspects of the present disclosure generally relate to wireless communications, and more specifically to reference signal design for communications with coverage enhancements and devices with limited communications resources, such as machine type communication (MTC) devices, enhanced or evolved MTC (eMTC) devices, and internet of things (IoT) devices. An example method generally includes determining a set of additional reference signals to transmit in a bundled transmission, based on a bundle length of the bundled transmission, and transmitting the bundled transmission, reference signals, and the additional reference signals, based on the determination.