There is disclosed a method for operating a wireless device (10), the wireless device (10) being D2D enabled. The method comprises entering, by the wireless device (10), an energy-saving mode; monitoring, by the wireless device (10), a pre-defined channel for a D2D wake-up signal at pre-defined times during the energy-saving mode; determining, by the wireless device (10), if a received wake-up signal is intended for the wireless device; and performing, by the wireless device (10), a wake-up procedure for D2D communication. There are also disclosed related devices and methods.