A wheel-well closure system for a motor vehicle has a wheel-arch delimiting a wheel-well and a wheel mounted in the wheel-well, the system comprising: a support structure connected to the wheel-arch; and a cover connected to the support structure and covering the wheel-well; wherein the cover is made of a flexible material and is secured to the wheel arch; wherein the system comprises a continuous annular part secured to the wheel facing the cover and rotating with the wheel about a horizontal axis; and wherein the support structure comprises an arm extending radially in front of the continuous annular part and against the cover, a steering movement of the wheel about a vertical axis causing the continuous annular to push the support structure and stretch the cover outside the wheel-well.