Enveloped double-stranded RNA (dsRNA) bacterial virus Pseudomonas phage ϕ6 has been developed into an advanced assembly system where purified virion proteins and genome segments self-assemble into infectious viral particles, inferring the assembly pathway. The most intriguing step is the membrane assembly occurring inside the bacterial cell. Here, we demonstrate that the middle virion shell, made of protein 8, associates with the expanded viral core particle and the virus-specific membrane vesicle.