Ominous CMake Warning

[wavefunction91]

I've been getting the following with CMake 3.20+

CMake Warning (dev) at src/CMakeLists.txt:259 (add_library):
  Policy CMP0115 is not set: Source file extensions must be explicit.  Run
  "cmake --help-policy CMP0115" for policy details.  Use the cmake_policy
  command to set the policy and suppress this warning.

  File:

    /global/cfs/projectdirs/m1027/dbwy/TA/new/tiledarray/src/TiledArray/config.h.in
This warning is for project developers.  Use -Wno-dev to suppress it.

CMake Warning (dev) at src/CMakeLists.txt:259 (add_library):
  Policy CMP0115 is not set: Source file extensions must be explicit.  Run
  "cmake --help-policy CMP0115" for policy details.  Use the cmake_policy
  command to set the policy and suppress this warning.

  File:

    /global/cfs/projectdirs/m1027/dbwy/TA/new/tiledarray/src/TiledArray/version.h.in
This warning is for project developers.  Use -Wno-dev to suppress it.

This is (obviously?) not consequential as everything seems to work as expected on generate / install, but would it be worth it to figure out a way to pacify it in case is does become consequential in a later CMake version?