diff --git a/src/timestamp.ml b/src/timestamp.ml
index ce06735b..f81bbfc1 100644
--- a/src/timestamp.ml
+++ b/src/timestamp.ml
@@ -30,6 +30,9 @@ type span = t
 module Span = struct
   type t = span
 
+  let to_int64_s t = t
+  let of_int64_s t = t
+
   let to_int_s t =
     let n = Int64.div t 1_000_000_L in
     Int64.to_int n