If the wrappers are not sealed with just water, use cornstarch glue instead. Mix 2 tablespoons of cornstarch with 1⁄3 cup of water in a small saucepan and bring to a boil over low heat. Stir often, until thickened into a glue-like consistency then cool until it is easy to handle. Use in place of the water on the corner of the wrapper to help seal them shut.