diff --git a/packages/num/num.1.5-1/opam b/packages/num/num.1.5-1/opam
index db2739b21db..df05149d1d7 100644
--- a/packages/num/num.1.5-1/opam
+++ b/packages/num/num.1.5-1/opam
@@ -19,6 +19,9 @@ build: [
 depends: [
   "ocaml" {>= "4.06.0"}
 ]
+depopts: [
+  "dune"
+]
 conflicts: [ "base-num" ]
 synopsis:
   "The legacy Num library for arbitrary-precision integer and rational arithmetic"