A surgical instrument comprising: (a) an ultrasonic transducer; (b) a shaft extending distally relative to the ultrasonic transducer; and (c) an end effector arranged at a distal end of the shaft, wherein the end effector comprises: (i) an ultrasonic blade configured to be driven by the ultrasonic transducer with ultrasonic energy, wherein the ultrasonic blade comprises: an upper treatment side, a lower treatment side arranged opposite of the upper treatment side, a first lateral side, and a second lateral side arranged opposite of the first lateral side, and (ii) a clamp arm movable relative to the ultrasonic blade for clamping tissue therebetween, wherein the clamp arm provides an RF electrode operable to seal tissue with RF energy, wherein the RF electrode comprises: a first electrode side portion, wherein the first electrode side portion is spaced laterally outward from the first lateral side of the ultrasonic blade by a first lateral gap distance, and a second electrode side portion spaced from the first electrode side portion, wherein the second electrode side portion is spaced laterally outward from the second lateral side of the ultrasonic blade by a second lateral gap distance, characterized in that each of the first lateral gap distance and the second lateral gap distance increases distally. (a) an ultrasonic transducer; (b) a shaft extending distally relative to the ultrasonic transducer; and (c) an end effector arranged at a distal end of the shaft, wherein the end effector comprises: (i) an ultrasonic blade configured to be driven by the ultrasonic transducer with ultrasonic energy, wherein the ultrasonic blade comprises: an upper treatment side, a lower treatment side arranged opposite of the upper treatment side, a first lateral side, and a second lateral side arranged opposite of the first lateral side, and (ii) a clamp arm movable relative to the ultrasonic blade for clamping tissue therebetween, wherein the clamp arm provides an RF electrode operable to seal tissue with RF energy, wherein the RF electrode comprises: a first electrode side portion, wherein the first electrode side portion is spaced laterally outward from the first lateral side of the ultrasonic blade by a first lateral gap distance, and a second electrode side portion spaced from the first electrode side portion, wherein the second electrode side portion is spaced laterally outward from the second lateral side of the ultrasonic blade by a second lateral gap distance, characterized in that each of the first lateral gap distance and the second lateral gap distance increases distally. (i) an ultrasonic blade configured to be driven by the ultrasonic transducer with ultrasonic energy, wherein the ultrasonic blade comprises: an upper treatment side, a lower treatment side arranged opposite of the upper treatment side, a first lateral side, and a second lateral side arranged opposite of the first lateral side, and an upper treatment side, a lower treatment side arranged opposite of the upper treatment side, a first lateral side, and a second lateral side arranged opposite of the first lateral side, and (ii) a clamp arm movable relative to the ultrasonic blade for clamping tissue therebetween, wherein the clamp arm provides an RF electrode operable to seal tissue with RF energy, wherein the RF electrode comprises: a first electrode side portion, wherein the first electrode side portion is spaced laterally outward from the first lateral side of the ultrasonic blade by a first lateral gap distance, and a second electrode side portion spaced from the first electrode side portion, wherein the second electrode side portion is spaced laterally outward from the second lateral side of the ultrasonic blade by a second lateral gap distance, characterized in that each of the first lateral gap distance and the second lateral gap distance increases distally. a first electrode side portion, wherein the first electrode side portion is spaced laterally outward from the first lateral side of the ultrasonic blade by a first lateral gap distance, and a second electrode side portion spaced from the first electrode side portion, wherein the second electrode side portion is spaced laterally outward from the second lateral side of the ultrasonic blade by a second lateral gap distance, characterized in that each of the first lateral gap distance and the second lateral gap distance increases distally.