An optical fiber coating die assembly is provided. The optical fiber coating die assembly includes a housing defining a guide chamber having an inlet for receiving optical fiber and an outlet, a guide die located at the outlet of the guide chamber, and a sizing die. The optical fiber coating die assembly also includes a coating applicator disposed between the guide die and the sizing die, and a tube operatively coupled to the inlet of the guide chamber and axially aligned with the chamber to receive the optical fiber fed into the guide chamber and provide a barrier to air flow.