FindPostgreSQL searches for non essential pg_type.h header

I'm getting the error below because it fails to find pg_type.h header file. While this header contains useful stuff for some programs not all programs need it (mine doesn't). Also the file isn't part of the headers distributed with libpq which is why it is missing on my system. When I remove the references to PostgreSQL_TYPE_INCLUDE_DIR from FindPostgreSQL.cmake my project configures, compiles and links.

CMake Error at /usr/share/cmake-3.7/Modules/FindPackageHandleStandardArgs.cmake:138 (message):
  Could NOT find PostgreSQL (missing: PostgreSQL_TYPE_INCLUDE_DIR) (found
  version "9.6.4")

Edited Aug 28, 2017 by Ben Boeckel

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information