A door checker assembly includes a checker housing secured to the door. An elongated checker arm is dimensioned for and slidingly received through the checker housing so that a first end is received in the door and a second end is pivotally mounted to a body of the vehicle. An elongated cover is received in the door that overlies and extends along substantially an entire length of the checker arm for blocking water from falling thereon. The cover has a mounting portion at one end that is fastened between the checker housing and an inner face of the door with the same fasteners that secure the checker housing. The cover is preferably a stamped metal structure.