Abstract: The present invention relates to an improved security device. The improved security device includes a U-shaped member which is designed to engage the shaft of a doorknob. Attached to the U-shaped member is a locking plate which has openings therein to receive either the latch of a deadbolt or the key head of a key inserted into a deadbolt. The improved security device, when in place, prevents entry into a dwelling by a person unlocking a deadbolt by preventing the rotation of a deadbolt latch or a key head inserted into the deadbolt.