It's a good question. Originally, there were two reasons why I didn't do this. First, the contract is slightly different, as I am also asserting purity. Thi

It's a good question. Originally, there were two reasons why I didn't do this. First, the contract is slightly different, as I am also asserting purity. This means that one @ImmutableValue knows that another @ImmutableValue (perhaps from a library package) is pure. Whereas, a class annotated with @Immutable might not be. Second, I developed this with the bank I work in in mind. They are still on flavours of Java 6 + 7. However, I am currently in mind to port this to Checker Framework, http://types.cs.washington.edu/checker-framework/ http://types.cs.washington.edu/checker-framework/ which is fully supported by the JDK8 compiler. I expect I'll still keep the separate annotation, but there are a lot of benefits from a tooling point of view to doing this (IDE support, gradle etc)