An ebullated bed hydroprocessing system is upgraded using a dual catalyst system that includes a heterogeneous catalyst and dispersed metal sulfide particles to improve the quality of vacuum residue. The improved quality of vacuum residue can be provided by one or more of reduced viscosity, reduced density (increased API gravity), reduced asphaltene content, reduced carbon residue content, reduced sulfur content, and reduced sediment. Vacuum residue of improved quality can be produced while operating the upgraded ebullated bed reactor at the same or higher severity, temperature, throughput and/or conversion. Similarly, vacuum residue of same or higher quality can be produced while operating the upgraded ebullated bed reactor at higher severity, temperature, throughput and/or conversion.