OpenMolcas+CheMPS2

When I try to compile OpenMolcas with CheMPS2 I get a problem with undefined references to certain HDF5 subroutines in 'chemps2_load2pdm.f90', which I assume are related to using Fortran 2003 with HDF5. But as far as I can tell, the HDF5 library I am using was compiled with Fortran 2003 support and I can find all the referenced functionalities when grepping for them in the HDF5 library. Any ideas on what might be going wrong?

Cheers!