A cover for the clutch of a roller blind. The clutch includes a sprocket rotationally driven through the application of tension to a chain or cord received at least partially about the sprocket. The clutch also includes an abutment member against which a stopper on the chain or cord bears to limit rotation of the sprocket in a pre-determined direction. The cover comprises a plate member fixed to the clutch and prevented from rotation with the sprocket. The cover has a notch sized to receive at least a portion of the stopper when the stopper contacts the abutment member.