diff --git a/src/management.ml b/src/management.ml
index 6978ff93..bc85d360 100644
--- a/src/management.ml
+++ b/src/management.ml
@@ -27,14 +27,12 @@ let mk_future_denom denom_key_signf
     let open Binary_formats in
     let h_denom_pub = h_pub in
     let h_section_name = Cstring_hash_64.hash section_name in
-    let anchor_time =
-      TimeAbsoluteNBO.{ v= Util.ptime_to_int64_us stamp_start }
-    in
+    let anchor_time = TimeAbsoluteNBO.{ v= Util.ptime_to_int64 stamp_start } in
     let duration_withdraw =
       let v =
         Ptime.diff stamp_start stamp_expire_withdraw
         |> Util.ptime_of_span_exn
-        |> Util.ptime_to_int64_us
+        |> Util.ptime_to_int64
       in
       TimeRelativeNBO.{ v }
     in
@@ -66,14 +64,12 @@ let mk_future_signkey signkey_signf
   let signkey_secmod_sig =
     let open Binary_formats in
     let exchange_pub = pub in
-    let anchor_time =
-      TimeAbsoluteNBO.{ v= Util.ptime_to_int64_us stamp_start }
-    in
+    let anchor_time = TimeAbsoluteNBO.{ v= Util.ptime_to_int64 stamp_start } in
     let duration =
       let v =
         Ptime.diff stamp_start stamp_expire
         |> Util.ptime_of_span_exn
-        |> Util.ptime_to_int64_us
+        |> Util.ptime_to_int64
       in
       TimeRelativeNBO.{ v }
     in
diff --git a/src/pg.ml b/src/pg.ml
index 8b3e39f8..6deccf9b 100644
--- a/src/pg.ml
+++ b/src/pg.ml
@@ -4,19 +4,12 @@
 module Caqti_type = struct
   include Caqti_type
 
-  let ptime_to_int64 ptime =
-    ptime |> Ptime.to_float_s |> Int64.of_float |> Result.ok
-
-  let ptime_of_int64 i =
-    match Ptime.of_float_s (Int64.to_float i) with
-    | None -> Fmt.error "ptime_of_int64 error: `%Ld` is not a valid ptime" i
-    | Some ts -> Ok ts
-
   (* we want to use int64 timestamps,
      not postgresql built-in timestamp type *)
   let ptime : Ptime.t Caqti_type.t =
-    Caqti_type.custom ~encode:ptime_to_int64 ~decode:ptime_of_int64
-      Caqti_type.(int64)
+    let encode i = Ok (Util.ptime_to_int64 i) in
+    let decode = Util.ptime_of_int64 in
+    Caqti_type.custom ~encode ~decode Caqti_type.(int64)
 end
 
 let pg_amount : Amount.t Caqti_type.t =
diff --git a/src/util.ml b/src/util.ml
index 36619bb6..608f3ed5 100644
--- a/src/util.ml
+++ b/src/util.ml
@@ -9,7 +9,12 @@ end
 
 (* -- Ptime -- *)
 
-let ptime_to_int64_us p = Int64.of_float (1_000_000. *. Ptime.to_float_s p)
+let ptime_to_int64 ptime = ptime |> Ptime.to_float_s |> Int64.of_float
+
+let ptime_of_int64 i =
+  match Ptime.of_float_s (Int64.to_float i) with
+  | None -> Fmt.error "ptime_of_int64 error: `%Ld` is not a valid ptime" i
+  | Some ts -> Ok ts
 
 let ptime_of_span_exn span =
   match Ptime.of_span span with