Satisfiability Modulo Theories (SMT) solvers are at the core of many software advances such as program analysis and verification which are highly safety-critical. Hence, to ensure the correctness of the solvers, there have been multiple fuzzing campaigns targeting different logics since 2009. In this paper, we propose a generative type-aware mutation strategy, which is a generalization of a type-aware operator mutation. We have realized the generative type-aware mutation and reported 158 bugs in Z3 and CVC4 including bugs from the versions released as early as 2016 in five months.