diff --git a/dev-ml/ppx_sexp_conv/ppx_sexp_conv-0.9.0-r1.ebuild b/dev-ml/ppx_sexp_conv/ppx_sexp_conv-0.9.0-r1.ebuild
index 1ed53355c24d3..7fa06c0bbf4b8 100644
--- a/dev-ml/ppx_sexp_conv/ppx_sexp_conv-0.9.0-r1.ebuild
+++ b/dev-ml/ppx_sexp_conv/ppx_sexp_conv-0.9.0-r1.ebuild
@@ -21,6 +21,7 @@ DEPEND="
 	dev-ml/ppx_optcomp:=
 	dev-ml/sexplib:=
 	dev-ml/ocaml-migrate-parsetree:=
+	dev-ml/ppx_traverse_builtins:=
 	"
 RDEPEND="${DEPEND}"
 DEPEND="${DEPEND} dev-ml/opam dev-ml/jbuilder"