A whipstock assembly includes a whipstock providing a ramped surface, and a mill releasably coupled to the whipstock with a shear bolt and providing a mill profile. A tension arm is pivotably coupled to the whipstock and movable between a stowed position, where the tension arm is received within a cavity defined in the ramped surface, and an engaged position, where an engagement head of the tension arm mates with the mill profile to assume at least a portion of a tensile load assumed by the shear bolt.