diff --git a/vendors/irmin-lmdb/irmin-lmdb.opam b/vendors/irmin-lmdb/irmin-lmdb.opam
index 2b14ba527..f3084ab5e 100644
--- a/vendors/irmin-lmdb/irmin-lmdb.opam
+++ b/vendors/irmin-lmdb/irmin-lmdb.opam
@@ -15,7 +15,7 @@ build-test: ["jbuilder" "runtest" "-p" name]
 
 depends: [
   "jbuilder" {build & >= "1.0+beta10"}
-  "irmin"    {>= "1.3.0"}
+  "irmin"    {>= "1.4.0"}
   "lmdb"     {>= "0.1"}
 ]