diff --git a/builder-web.opam b/builder-web.opam
index 4181928..5f88b62 100644
--- a/builder-web.opam
+++ b/builder-web.opam
@@ -19,6 +19,7 @@ depends: [
   "caqti"
   "caqti-lwt"
   "caqti-driver-sqlite3"
+  "pbkdf"
 ]
 
 synopsis: "Web interface for builder"