diff --git a/otr.opam b/otr.opam
index 9fbd4e1..dbda1fb 100644
--- a/otr.opam
+++ b/otr.opam
@@ -18,7 +18,7 @@ depends: [
   "mirage-crypto-rng" {with-test}
 ]
 build: [
-  ["dune" "subst"] {pinned}
+  ["dune" "subst"] {dev}
   ["dune" "build" "-p" name "-j" jobs]
   ["dune" "runtest" "-p" name "-j" jobs] {with-test}
 ]