Example implementations relate to tracking memory unit errors on a memory device. In example implementations, a memory device may include on-die error-correcting code (ECC) and a plurality of error counters. One of the plurality of error counters may count errors, detected by the on-die ECC, in a memory unit on the memory device. A post package repair (PPR) may be initiated on the memory device in response to a determination that a value of the one of the plurality of error counters equals a threshold value.