diff --git a/src/libmtime.f90 b/src/libmtime.f90
index 7ed863a2b6fe1cc51aadc9ad687858c022ae299a..95c48b4aed4cd48b670b0e8b9a7b4604fa630d4c 100644
--- a/src/libmtime.f90
+++ b/src/libmtime.f90
@@ -145,7 +145,7 @@ end module mtime_calendar
 
 MODULE mtime_juliandelta
   !
-  USE, INTRINSIC :: iso_c_binding, ONLY: c_int64_t, c_char, c_ptr, c_loc, c_associated
+  USE, INTRINSIC :: iso_c_binding, ONLY: c_int64_t, c_char, c_ptr, c_loc, c_associated, c_f_pointer
   !
   IMPLICIT NONE
   !