The invention relates to a method for the retroactive strengthening of a fastening means inserted into a drilled hole, which fastening means is already in its mounted state, having the following steps: ° mounting an injection washer, which has a central hole, a filling opening and a ventilation opening, onto the fastening means to be strengthened, ° filling cavities present between the fastening means and the drilled hole by injecting injection resin through the filling opening.
