diff --git a/src/hdf5_interface.cpp b/src/hdf5_interface.cpp
index 4badc0441c..cecf283ac1 100644
--- a/src/hdf5_interface.cpp
+++ b/src/hdf5_interface.cpp
@@ -748,6 +748,8 @@ const hid_t H5TypeMap<int>::type_id = H5T_NATIVE_INT;
 template<>
 const hid_t H5TypeMap<unsigned long>::type_id = H5T_NATIVE_ULONG;
 template<>
+const hid_t H5TypeMap<unsigned int>::type_id = H5T_NATIVE_UINT;
+template<>
 const hid_t H5TypeMap<int64_t>::type_id = H5T_NATIVE_INT64;
 template<>
 const hid_t H5TypeMap<double>::type_id = H5T_NATIVE_DOUBLE;
diff --git a/src/nuclide_header.F90 b/src/nuclide_header.F90
index 47a2d700a1..5504c1fd5e 100644
--- a/src/nuclide_header.F90
+++ b/src/nuclide_header.F90
@@ -122,7 +122,7 @@ module nuclide_header
 
   ! Arbitrary value to indicate invalid cache state for elastic scattering
   ! (NuclideMicroXS % elastic)
-  real(8), parameter :: CACHE_INVALID = dble(Z"FFE0000000000000")
+  real(8), parameter :: CACHE_INVALID = -1
 
   type, bind(C) :: NuclideMicroXS
     ! Microscopic cross sections in barns