Avoid Importing Umbrella Headers Outside of Swift

Hi, I am trying to avoid Importing Umbrella Headers Outside of Swift and Swift.h in a framework, for the Swift.h, I can use SWIFT_TYPEDEFS to to determine if the Swift.h imported

#if !defined(SWIFT_TYPEDEFS)
#error Do not include this header file outside of Swift.h
#endif

But I don't know if Swift Compiler has a specific #define value when reading umbrella heads, does anyone know? Thanks