diff --git a/dune-project b/dune-project
index e82c37fec4..0407b41f34 100644
--- a/dune-project
+++ b/dune-project
@@ -29,7 +29,7 @@
   menhir
   menhirLib
   menhirSdk
-  yojson)
+  (yojson (>= 1.6)))
  (depopts
   ocamlfind)
  (conflicts
diff --git a/js_of_ocaml-compiler.opam b/js_of_ocaml-compiler.opam
index 0a3cf50d9c..131e3e5c12 100644
--- a/js_of_ocaml-compiler.opam
+++ b/js_of_ocaml-compiler.opam
@@ -24,7 +24,7 @@ depends: [
   "menhir"
   "menhirLib"
   "menhirSdk"
-  "yojson"
+  "yojson" {>= "1.6"}
   "odoc" {with-doc}
 ]
 depopts: ["ocamlfind"]