diff --git a/coq-itree-extra.opam b/coq-itree-extra.opam
index 71a36057..4888f210 100644
--- a/coq-itree-extra.opam
+++ b/coq-itree-extra.opam
@@ -11,12 +11,11 @@ tags: ["org:deepspec"]
 homepage: "https://github.com/DeepSpec/InteractionTrees"
 bug-reports: "https://github.com/DeepSpec/InteractionTrees/issues"
 depends: [
-  "dune" {>= "3.14"}
+  "dune" {>= "2.6"}
   "coq"
   "coq-ext-lib"
   "coq-paco"
   "coq-itree"
-  "odoc" {with-doc}
 ]
 dev-repo: "git+https://github.com/DeepSpec/InteractionTrees.git"
 build: [
diff --git a/coq-itree.opam b/coq-itree.opam
index 1aea01dd..952150fb 100644
--- a/coq-itree.opam
+++ b/coq-itree.opam
@@ -18,14 +18,13 @@ tags: ["org:deepspec"]
 homepage: "https://github.com/DeepSpec/InteractionTrees"
 bug-reports: "https://github.com/DeepSpec/InteractionTrees/issues"
 depends: [
-  "dune" {>= "3.14"}
+  "dune" {>= "2.6"}
   "coq" {>= "8.14"}
   "coq-ext-lib" {>= "0.11.1"}
   "coq-paco" {>= "4.2.1"}
-  "odoc" {with-doc}
 ]
 build: [
-  ["dune" "subst"] {dev}
+  ["dune" "subst"] {pinned}
   [
     "dune"
     "build"
diff --git a/dune-project b/dune-project
index 6ead56e3..6e8d191c 100644
--- a/dune-project
+++ b/dune-project
@@ -1,5 +1,5 @@
-(lang dune 3.14)
-(using coq 0.7)
+(lang dune 2.6)
+(using coq 0.2)
 (name coq-itree)
 (version dev)
 (maintainers "Li-yao Xia <lysxia@gmail.com>")