diff --git a/CHANGES.md b/CHANGES.md
index 61a00a63..34e62f45 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,4 +1,21 @@
 
+# 0.9
+
+- breaking: require OCaml 5
+  * no further need for a preprocessor
+  * forkjoin not longer optional
+
+- moonpool-lwt: large changes, including a Runner that runs
+    inside `Lwt_unix`'s event loop and can thus use any `_ Lwt.t` function
+- remove bounded_queue
+- fix core: better repropagating of errors
+- add `Fut.{cancel,try_cancel}`
+- perf: `await` on immediately ready timer queues its task
+- feat: add `Moonpool.yield`
+
+- deprecate moonpool.sync
+- deprecate moonpool_io
+
 # 0.8
 
 - api(fut): make alias `'a Fut.t = 'a Picos.Computation.t` public
diff --git a/dune-project b/dune-project
index ceae9ab2..f5168e14 100644
--- a/dune-project
+++ b/dune-project
@@ -2,7 +2,7 @@
 (using mdx 0.2)
 
 (name moonpool)
-(version 0.8)
+(version 0.9)
 (generate_opam_files true)
 (source
  (github c-cube/moonpool))
diff --git a/moonpool-io.opam b/moonpool-io.opam
index 5e943b0a..e2c3c955 100644
--- a/moonpool-io.opam
+++ b/moonpool-io.opam
@@ -1,6 +1,6 @@
 # This file is generated by dune, edit dune-project instead
 opam-version: "2.0"
-version: "0.8"
+version: "0.9"
 synopsis: "Async IO for moonpool, relying on picos (experimental)"
 maintainer: ["Simon Cruanes"]
 authors: ["Simon Cruanes"]
diff --git a/moonpool-lwt.opam b/moonpool-lwt.opam
index 982f8d03..0f79e676 100644
--- a/moonpool-lwt.opam
+++ b/moonpool-lwt.opam
@@ -1,6 +1,6 @@
 # This file is generated by dune, edit dune-project instead
 opam-version: "2.0"
-version: "0.8"
+version: "0.9"
 synopsis: "Event loop for moonpool based on Lwt-engine (experimental)"
 maintainer: ["Simon Cruanes"]
 authors: ["Simon Cruanes"]
diff --git a/moonpool.opam b/moonpool.opam
index 46fb6b69..40afc887 100644
--- a/moonpool.opam
+++ b/moonpool.opam
@@ -1,6 +1,6 @@
 # This file is generated by dune, edit dune-project instead
 opam-version: "2.0"
-version: "0.8"
+version: "0.9"
 synopsis: "Pools of threads supported by a pool of domains"
 maintainer: ["Simon Cruanes"]
 authors: ["Simon Cruanes"]
diff --git a/src/lwt/moonpool_lwt.mli b/src/lwt/moonpool_lwt.mli
index d70863b8..7447dea5 100644
--- a/src/lwt/moonpool_lwt.mli
+++ b/src/lwt/moonpool_lwt.mli
@@ -6,7 +6,10 @@
 
     {b NOTE}: this is experimental and might change in future versions.
 
-    @since 0.6 *)
+    @since 0.6
+
+    The API has entirely changed since 0.9 , see
+    https://github.com/c-cube/moonpool/pull/37 *)
 
 module Fut = Moonpool.Fut