Tomato leaves curling/folding

[ju1234]

One of the three tomato plants i have possibly has a problem or it may be thing with this variety. All the leaves appear to be slightly folded. The leave is kind of curled along the longitudinal axis, just slightly folded. All of the leaves are like that. Otherwise the plant is fine. Growth seems to be normal. It is green, flowering, and soon to set fruit. There are no bugs. Is this folding normal? Thanks.