An electrical connector assembly comprises a stiffener including a base with a first portion and a second portion, insulative housing, a load plate and a lever. An embossed portion is formed on the base and has substantial distance to a first end of the first portion. An insulative housing is disposed between the first portion and the second portion. A load plate is pivotally mounted on the second portion of the stiffener. A lever is pivotally assembled to the first portion of the stiffener to lock the load plate and includes a retaining portion adjacent to the embossed portion to abut against the lever when it is rotated.