diff --git a/packages/h1_parser/h1_parser.0.0.2/opam b/packages/h1_parser/h1_parser.0.0.2/opam
index 180efd11a0b..7dc7d29c784 100644
--- a/packages/h1_parser/h1_parser.0.0.2/opam
+++ b/packages/h1_parser/h1_parser.0.0.2/opam
@@ -9,7 +9,7 @@ bug-reports: "https://github.com/anuragsoni/h1/issues"
 depends: [
   "dune" {>= "2.8"}
   "ocaml" {>= "4.11.0"}
-  "cohttp" {>= "4.0.0"}
+  "cohttp" {>= "4.0.0" & < "6.0.0~~"}
   "base_bigstring"
   "base" {with-test}
   "alcotest" {with-test}