Compatibility issue with prost 0.12?

[brocaar]

I'm using pbjson 0.5.1 and I had no issues while using prost 0.11. While trying to upgrade prost to 0.12.0 which was released last week, I'm getting lots of errors:

error[E0277]: the trait bound `pbjson_types::Struct: prost::Message` is not satisfied
     |
282  | #[derive(Clone, PartialEq, ::prost::Message)]
     |                            ^^^^^^^^^^^^^^^^ the trait `prost::Message` is not implemented for `pbjson_types::Struct`
     |
     = help: the following other types implement trait `prost::Message`:
               bool
               i32
               i64
               u32
               u64
               f32
               f64
               prost_types::compiler::Version
             and 339 others
note: required by a bound in `message::encoded_len`
    --> /home/brocaar/.cargo/registry/src/index.crates.io-6f17d22bba15001f/prost-0.12.0/src/encoding.rs:1121:12
     |
1119 |     pub fn encoded_len<M>(tag: u32, msg: &M) -> usize
     |            ----------- required by a bound in this function
1120 |     where
1121 |         M: Message,
     |            ^^^^^^^ required by this bound in `encoded_len`
     = note: this error originates in the derive macro `::prost::Message` (in Nightly builds, run with -Z macro-backtrace for more info)

Is this a known issue?