Methods and apparatus are provided for demodulation reference signal configuration in a shared radio spectrum system. A method performed by a wireless device (110, 200) is provided. The wireless device (200) operating in a communications system, wherein the communications system comprises radio spectrum shared by a plurality of radio access technologies. The method comprising obtaining (600) a configuration for a demodulation reference signal, DMRS, wherein the DMRS comprises a pattern using common resource elements of at least two of the plurality of radio access technologies and transmitting or receiving (630) a data transmission based on the obtained demodulation reference signal. A method performed by a network node (160) is provided. The method comprises the network node determining (700) a configuration for a demodulation reference signal, DMRS, wherein the DMRS comprises a pattern using common resource elements of at least two of the plurality of radio access technologies and receiving or transmitting (720) a data transmission based on the determined configuration for the demodulation reference signal.