diff --git a/fortran/tuvx.F90 b/fortran/tuvx.F90
index 55d8e1cb..d4b61127 100644
--- a/fortran/tuvx.F90
+++ b/fortran/tuvx.F90
@@ -18,7 +18,7 @@ module musica_tuvx
       function create_tuvx_c(config_path, error) bind(C, name="CreateTuvx")
          use musica_util, only: error_t_c
          import c_ptr, c_int, c_char
-         character(kind=c_char), intent(in) :: config_path(*)
+         character(len=1, kind=c_char), intent(in) :: config_path(*)
          type(error_t_c), intent(inout)     :: error
          type(c_ptr)                        :: create_tuvx_c
       end function create_tuvx_c
diff --git a/src/tuvx/interface.F90 b/src/tuvx/interface.F90
index 4bcfc594..d946594d 100644
--- a/src/tuvx/interface.F90
+++ b/src/tuvx/interface.F90
@@ -99,9 +99,9 @@ function interal_get_grid(grid_map, c_grid_name, c_grid_name_length, c_grid_unit
     
       ! arguments
       type(c_ptr), intent(in), value                   :: grid_map
-      character(kind=c_char), dimension(*), intent(in) :: c_grid_name
+      character(len=1, kind=c_char), dimension(*), intent(in) :: c_grid_name
       integer(kind=c_size_t), value                    :: c_grid_name_length
-      character(kind=c_char), dimension(*), intent(in) :: c_grid_units
+      character(len=1, kind=c_char), dimension(*), intent(in) :: c_grid_units
       integer(kind=c_size_t), value                    :: c_grid_units_length
       integer(kind=c_int), intent(out)                 :: error_code