diff --git a/src/HDF5_utilities.f90 b/src/HDF5_utilities.f90
index 22a6e00e5..7655788bb 100644
--- a/src/HDF5_utilities.f90
+++ b/src/HDF5_utilities.f90
@@ -312,7 +312,7 @@ subroutine HDF5_addAttribute_str(loc_id,attrLabel,attrValue,path)
   logical        :: attrExists
   integer        :: hdferr
   character(len=:), allocatable :: p
-  character(len=:,kind=C_CHAR), allocatable,target :: attrValue_
+  character(len=len_trim(attrValue)+1,kind=C_CHAR), target :: attrValue_
   type(c_ptr), target, dimension(1) :: ptr