A format for well-behaved translations between structural operational specifications is derived from a notion of distributive law morphism, previously studied by Power and Watanabe. 1998 ACM Subject Classification F.3.2 Semantics of Programming Languages – Operational semantics Keywords and phrases coalgebra, bialgebra, distributive law, structural operational semantics Digital Object Identifier 10.4230/LIPIcs.CALCO.2015.190