diff --git a/lib/rsync_store.ml b/lib/rsync_store.ml
index dfc15b6f..6d94ea30 100644
--- a/lib/rsync_store.ml
+++ b/lib/rsync_store.ml
@@ -14,6 +14,7 @@ type mode =
   | Copy
   | Hardlink
   | Hardlink_unsafe
+[@@deriving sexp]
 
 type t = {
   path : string;
diff --git a/lib/rsync_store.mli b/lib/rsync_store.mli
index ee0d69d0..ce92da42 100644
--- a/lib/rsync_store.mli
+++ b/lib/rsync_store.mli
@@ -8,6 +8,7 @@ type mode =
   | Hardlink_unsafe (** Reasonably fast and uses less disk space, but no
                         checksum verification. Only for testing during
                         development, do not use in production. *)
+[@@deriving sexp]
 
 val create : path:string -> ?mode:mode -> unit -> t Lwt.t
 (** [create ~path ?mode ()] creates a new rsync store where everything will
diff --git a/lib/store_spec.ml b/lib/store_spec.ml
index adb8366f..5aadfd79 100644
--- a/lib/store_spec.ml
+++ b/lib/store_spec.ml
@@ -1,6 +1,7 @@
 (** Configuration information to set up a store. *)
 
 open Lwt.Infix
+open Sexplib.Conv
 
 type t = [
   | `Btrfs of string  (* Path *)
@@ -8,7 +9,7 @@ type t = [
   | `Rsync of (string * Rsync_store.mode)  (* Path for the root of the store *)
   | `Xfs of string    (* Path *)
   | `Docker of string (* Path *)
-]
+][@@deriving sexp]
 
 let is_absolute path = not (Filename.is_relative path)