An ultrasonic surgical instrument includes an end effector, a shaft assembly, and a waveguide grounding feature. The end effector includes an ultrasonic blade and a clamp arm movable between an open position and a closed position. The shaft assembly includes a proximal shaft portion extending along a longitudinal axis, an acoustic waveguide extending proximally from the ultrasonic blade, a distal shaft portion extending along a distal axis, and an articulation section interposed between the proximal shaft portion and the distal shaft portion. The articulation section can deflect the distal shaft portion and the end effector relative to the longitudinal axis between a straight configuration and an articulated configuration. The waveguide grounding feature inhibits the ultrasonic blade from shifting relative to the clamp arm along the distal axis as the end effector is driven between the straight configuration and the articulated configuration.