diff --git a/containers-data.opam b/containers-data.opam
new file mode 100644
index 00000000..ee4e55b2
--- /dev/null
+++ b/containers-data.opam
@@ -0,0 +1,27 @@
+opam-version: "2.0"
+version: "2.8.1"
+author: "Simon Cruanes"
+maintainer: "simon.cruanes.2007@m4x.org"
+synopsis: "A set of advanced datatypes for containers"
+build: [
+  ["dune" "build" "-p" name "-j" jobs]
+  ["dune" "build" "@doc" "-p" name ] {with-doc}
+  ["dune" "runtest" "-p" name "-j" jobs] {with-test}
+]
+depends: [
+  "ocaml" { >= "4.03.0" }
+  "dune" { >= "1.1" }
+  "containers" { = version }
+  "seq"
+  "qtest" { with-test }
+  "qcheck" { with-test }
+  "ounit" { with-test }
+  "iter" { with-test }
+  "gen" { with-test }
+  "odoc" { with-doc }
+]
+tags: [ "containers" "RAL" "functional" "vector" "okasaki" ]
+homepage: "https://github.com/c-cube/ocaml-containers/"
+doc: "https://c-cube.github.io/ocaml-containers"
+dev-repo: "git+https://github.com/c-cube/ocaml-containers.git"
+bug-reports: "https://github.com/c-cube/ocaml-containers/issues/"
diff --git a/containers-thread.opam b/containers-thread.opam
new file mode 100644
index 00000000..7c2ba13a
--- /dev/null
+++ b/containers-thread.opam
@@ -0,0 +1,27 @@
+opam-version: "2.0"
+version: "2.8.1"
+author: "Simon Cruanes"
+maintainer: "simon.cruanes.2007@m4x.org"
+synopsis: "An extension of containers for threading"
+build: [
+  ["dune" "build" "-p" name "-j" jobs]
+  ["dune" "build" "@doc" "-p" name ] {with-doc}
+  ["dune" "runtest" "-p" name "-j" jobs] {with-test}
+]
+depends: [
+  "ocaml" { >= "4.03.0" }
+  "dune" { >= "1.1" }
+  "base-threads"
+  "dune-configurator"
+  "containers" { = version }
+  "qtest" { with-test }
+  "qcheck" { with-test }
+  "ounit" { with-test }
+  "uutf" { with-test }
+  "odoc" { with-doc }
+]
+tags: [ "containers" "thread" "semaphore" "blocking queue" ]
+homepage: "https://github.com/c-cube/ocaml-containers/"
+doc: "https://c-cube.github.io/ocaml-containers"
+dev-repo: "git+https://github.com/c-cube/ocaml-containers.git"
+bug-reports: "https://github.com/c-cube/ocaml-containers/issues/"