diff --git a/packages/irmin-server/irmin-server.3.9.0/opam b/packages/irmin-server/irmin-server.3.9.0/opam
index 08cd17a7c0d..e28f8e50164 100644
--- a/packages/irmin-server/irmin-server.3.9.0/opam
+++ b/packages/irmin-server/irmin-server.3.9.0/opam
@@ -18,7 +18,7 @@ depends: [
   "cmdliner" {>= "1.0.4"}
   "logs" {>= "0.7.0"}
   "lwt" {>= "5.4.0"}
-  "conduit-lwt-unix"
+  "conduit-lwt-unix" {>="6.0.0"}
   "websocket-lwt-unix"
   "cohttp-lwt-unix"
   "ppx_blob" {>= "0.7.2"}