diff --git a/packages/ptt.0.0.1~dev/opam b/packages/ptt.0.0.1~dev/opam
index 7fec452..8b2ba48 100644
--- a/packages/ptt.0.0.1~dev/opam
+++ b/packages/ptt.0.0.1~dev/opam
@@ -33,7 +33,7 @@ depends: [
   "irmin-unix" {>= "2.10.0"}
   "ca-certs"
   "cmdliner"
-  "irmin" {>= "2.10.0"}
+  "irmin" {>= "2.10.0" & < "3.0.0"}
   "mirage-kv"
   "dns-client" {>= "5.0.0"}
   "mirage-clock-unix" {>= "3.1.0"}