Abstract: A locking apparatus for an electrically actuated garage door opener assembly is disclosed for preventing the unauthorized entry into a home or building. The locking apparatus comprises an electric solenoid and associated plunger and is electrically connected to the electrically actuated garage door opener in order to selective lock and unlock the garage door. In the deactivated condition of the opener, the plunger provides a locking mechanism. When the opener is activated, the solenoid is energized and the plunger is withdrawn from its locking position, thus permitting the door to open. An important feature of the present invention is a sensing mechanism which senses the locked and unlocked position of the solenoid plunger. If the plunger is in the locked position, the sensor will prevent actuation of the opener, thereby avoiding damage to the door or opener.