Process for minimizing the amount of catalyst fines in a flue gas from a catalyst regenerator. Pyrolysis oil is injected into the reaction zone, preferably downstream from the feedstream inlet. The catalyst fines will be passed along with the hydrocarbon effluent stream and can be removed with a filter or other similar device. The amount of pyrolysis oil can be controlled, for example, based upon the opacity of the flue gas from the catalyst regenerator, or based upon the amount of catalyst injected into the reaction zone.