diff --git a/ocsigenserver.opam b/ocsigenserver.opam
index 3754d3850..745f32786 100644
--- a/ocsigenserver.opam
+++ b/ocsigenserver.opam
@@ -57,8 +57,8 @@ depends: [
   "re" {>= "1.11.0"}
   "cryptokit"
   "ipaddr" {>= "2.1"}
-  "cohttp-lwt-unix" {>= "5.0.0" & < "6.0.0~"}
-  "conduit-lwt-unix" {>= "2.0.0"}
+  "cohttp-lwt-unix" {>= "5.0.0" & < "6.0"}
+  "conduit-lwt-unix" {>= "2.0.0" & < "7.0"}
   "xml-light"
   "camlzip"
 ]