A plastic bag having a reclosable plastic zipper is provided with a tamper-evident, non-reclosable peel seal formed by applying an adhesive to a treated strip adjacent to the interlocking zipper. The treatment is preferably by corona discharge, which causes the adhesive used to provide the peel seal to preferentially adhere to the treated strip when the peel seal is broken. A method for manufacturing the reclosable plastic zipper includes the steps of extruding a zipper profile, treating a portion of its surface, preferably by corona discharge, applying an adhesive to the treated portion, slitting the profile lengthwise, and folding over one of the resulting sides of the zipper to interlock them with one another.