A vacuum pump having components that are subject to wear may be adjusted to compensate for the wear. In some instances, a vacuum pump may include a housing and an impeller disposed at least partially within the housing. A gap between the housing and the impeller may be adjustable to compensate for wear. In some cases, the housing may include a ring that may be moved to adjust a tolerance (or gap) between the ring and the impeller. In some instances, the ring may be rotated to adjust this gap. In other instances, the ring may be translated to adjust the tolerance.