An optical communications module includes a housing that accommodates at least one optical receptacle having a cylindrical connector portion. The module further includes at least one deformable constraining member made of a material having a Young's modulus that allows the deformable constraining member to take on an initial deformity upon application of a compression force, but permits only a partial reversal of the deformity upon reduction or removal of the compression force. The initial deformity is created when the deformable constraining member is pressed against the cylindrical connector portion during assembly of the module. The initial deformity includes a deformed contour portion that conforms to at least a part of the cylindrical connector portion of the optical receptacle and prevents wiggling of the cylindrical connector portion after the cylindrical connector portion is pushed during assembly into an alignment notch provided in a lower housing portion of the module.