Example implementations relate to using a spare memory on a memory module. In example implementations, a memory module may have a plurality of memories, including default memories and a spare memory. A plurality of data buffers on the memory module may select data nibbles from the plurality of memories such that when a default memory is identified as defective, a data nibble is selected from the spare memory and not from the defective default memory. A data nibble selected from the default memory may be in a first position in an output of the memory module when the default memory is functional. A data nibble selected from the spare memory may be in a second position in the output of the memory module.