Declaring a TMap as a UPROPERTY fails to compile with a boolean

Declaring a TMap< [type], bool> will fail to compile if it is declared as a UPROPERTY. The error seems to be with the bool because TMap< [type], int8> will compile as a UPROPERTY.

1. Open UE4Editor (any project)
2. Add Code to project based on Actor (MyActor)
3. In MyActor.h add the following:

   UPROPERTY()
   TMap<FName, bool> TestTMap;
   

4. Compile

UPROPERTY TMap prevents compile