Android provides a WakeLock mechanism for application developers to ensure the proper execution of applications without having to enter the sleep state of a device. When using the WakeLock mechanism, application developers should bear the responsibility of adequately releasing the acquired lock. Otherwise, the energy will unnecessarily be wasted due to a locked application. This paper presents a scheme, called WakeScope, to handle WakeLock misuse. The scheme is designed to detect and notify of a misuse case of WakeLock handling, which may arise with an application and even with an Android runtime system, and thus provides a practical tool to prevent energy waste in mobile devices. Our experiments with real applications show that WakeScope accurately detects the misused case, with runtime overhead of approximately 1.2% in CPU usage.