A covering for an architectural opening is provided. The covering may include a rotatable roller, a shade attached to the rotatable roller, and a shade actuation system. The shade may be wrappable about the roller. The shade may include two laterally-separable sheets interconnected by a plurality of vertically-spaced vanes. The shade actuation system may be selectively engageable with a confronting face of one of the two laterally-separable sheets. Engagement of the shade actuation system and the one of the two laterally-separable sheets may restrict movement of the one of the two laterally-separable sheets relative to the other of the two laterally-separable sheets.