Systems and methods are disclosed herein that relate to the use of a Device-to-Device (D2D) sidelink, e.g., in a licensed spectrum, to assist with clear channel assessment in an unlicensed spectrum. In doing so, the hidden node problem and / or the exposed node problem can be mitigated. In some embodiments, a method of operation of a wireless device in a cellular communications network comprises performing a sidelink-assisted clear channel assessment (SLA-CCA) procedure to determine whether to transmit on an unlicensed channel. The SLA-CCA procedure is a Clear Channel Assessment (CCA) procedure that is assisted by information received by the wireless device from one or more other wireless devices over a D2D sidelink in a licensed spectrum. The method further comprises, upon determining to transmit on the unlicensed channel as a result of performing the SLA-CCA procedure, transmitting a transmission on the unlicensed channel.