diff --git a/irmin-client.opam b/irmin-client.opam
index 9497aa836d..f67d9bcf76 100644
--- a/irmin-client.opam
+++ b/irmin-client.opam
@@ -24,6 +24,7 @@ depends: [
   "irmin-test" {= version & with-test}
   "alcotest-lwt" {with-test & >= "1.8.0"}
   "irmin-watcher" {with-test & >= "0.5.0"}
+  "mirage-crypto-rng-lwt" {with-test & >= "1.1.0"}
 ]
 build: [
   ["dune" "subst"] {pinned}
diff --git a/test/irmin-client/dune b/test/irmin-client/dune
index 3ce7abc817..4c0627d9b9 100644
--- a/test/irmin-client/dune
+++ b/test/irmin-client/dune
@@ -8,6 +8,7 @@
   websocket-lwt-unix
   conduit-lwt-unix
   alcotest-lwt
+  mirage-crypto-rng-lwt
   irmin-test
   irmin-watcher)
  (enabled_if
diff --git a/test/irmin-client/util.ml b/test/irmin-client/util.ml
index 14296af0e3..60a3e63404 100644
--- a/test/irmin-client/util.ml
+++ b/test/irmin-client/util.ml
@@ -15,6 +15,9 @@
  *)
 
 open Lwt.Infix
+
+let () = Mirage_crypto_rng_lwt.initialize (module Mirage_crypto_rng.Fortuna)
+
 module Store = Irmin_mem.KV.Make (Irmin.Contents.String)
 module Client = Irmin_client_unix.Make (Store)
 module Server = Irmin_server_unix.Make (Store)