diff --git a/builder-web.opam b/builder-web.opam
index 5f88b62..e937e3f 100644
--- a/builder-web.opam
+++ b/builder-web.opam
@@ -20,6 +20,7 @@ depends: [
   "caqti-lwt"
   "caqti-driver-sqlite3"
   "pbkdf"
+  "mirage-crypto-rng"
 ]
 
 synopsis: "Web interface for builder"