A needle guard for a syringe including tabs and preferably springboards disposed on the needle guard configured to engage a luer lock to prevent rotation of the luer lock during needle exchange. The body of the needle guard preferably includes springboards which are in communication with tabs disposed on the shield when the shield is in a first, retracted position. Inward or radial depression of the tabs forces the springboards to contact the luer lock and prevent rotation of the luer lock. The needle guard further comprises a slot disposed near the proximal end of the shield which is configured to engage an end tab disposed near the distal end of the body. When the needle guard is activated, the shield slides to a second, extended position and the end tab enters into the slot to lock the shield in the extended position.