Provided is a filter assembly including at least one end cap and at least one retainer mechanically locked to the end cap in a cavity and defining a region into which the bonding agent can flow to form a mechanical interlock with the retainer. Even if the bonding agent does not fully adhere to the end cap, the filter media will be secured in the end cap via the mechanical interlock of the bonding agent and retainer, thereby preventing end cap separation from the element.