diff --git a/packages/mirage-unikernel-tlstunnel-hvt.0.0.1/opam b/packages/mirage-unikernel-tlstunnel-hvt.0.0.1/opam
index 41ec047..63f26de 100644
--- a/packages/mirage-unikernel-tlstunnel-hvt.0.0.1/opam
+++ b/packages/mirage-unikernel-tlstunnel-hvt.0.0.1/opam
@@ -2,7 +2,7 @@
 opam-version: "2.0"
 name: "mirage-unikernel-tlstunnel-hvt"
 depends: [ "arp" { >= "2.3.0" & < "3.0.0"}
-           "dns-certify" { >= "4.6.3"}
+           "dns-certify" { >= "4.6.3" & < "5.0.0"}
            "ethernet" { >= "2.2.0" & < "3.0.0"}
            "functoria-runtime" 
            "lwt"