diff --git a/opam b/opam
index d0553bc169c5488d2a3f58c02e57a53a538bbff3..cb524aa9e24774b32d85478a59eac1df2b89ce7a 100644
--- a/opam
+++ b/opam
@@ -132,6 +132,7 @@ depends: [
   "ocaml" { >= "4.14.0" }
   "ocamlgraph" { >= "2.0.0" }
   "ocamlgraph" { with-test & >= "2.1.0" }
+  "ocp-indent" { with-dev-setup & >= "1.8.1" }
   "odoc" { with-doc }
   "unionFind" { >= "20220107" }
   "why3" { >= "1.7.1" & (< "1.8.0" | !with-test) }