diff --git a/CHANGELOG.md b/CHANGELOG.md
index ad86755b..087624ae 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## Unreleased
 
+## [0.9.0]
+
 ### Changed
 
 * The blanket implementations for `FromPyObject` for `&T` and `&mut T` are no longer specializable. Implement `PyTryFrom` for your type to control the behavior of `FromPyObject::extract()` for your types.
diff --git a/Cargo.toml b/Cargo.toml
index 983ce2d8..386864e4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "pyo3"
-version = "0.8.5"
+version = "0.9.0-alpha.1"
 description = "Bindings to Python interpreter"
 authors = ["PyO3 Project and Contributors <https://github.com/PyO3>"]
 readme = "README.md"
@@ -27,7 +27,7 @@ num-complex = { version = ">= 0.2", optional = true }
 num-traits = "0.2.8"
 parking_lot = { version = "0.10", features = ["nightly"] }
 paste = "0.1.6"
-pyo3cls = { path = "pyo3cls", version = "=0.8.5" }
+pyo3cls = { path = "pyo3cls", version = "=0.9.0-alpha.1" }
 unindent = "0.1.4"
 
 [dev-dependencies]
diff --git a/README.md b/README.md
index bf9c9efc..50b99258 100644
--- a/README.md
+++ b/README.md
@@ -50,7 +50,7 @@ name = "string_sum"
 crate-type = ["cdylib"]
 
 [dependencies.pyo3]
-version = "0.8.5"
+version = "0.9.0-alpha.1"
 features = ["extension-module"]
 ```
 
@@ -95,7 +95,7 @@ Add `pyo3` to your `Cargo.toml` like this:
 
 ```toml
 [dependencies]
-pyo3 = "0.8.5"
+pyo3 = "0.9.0-alpha.1"
 ```
 
 Example program displaying the value of `sys.version` and the current user name:
diff --git a/guide/src/get_started.md b/guide/src/get_started.md
index ae1e864c..5d531061 100644
--- a/guide/src/get_started.md
+++ b/guide/src/get_started.md
@@ -44,7 +44,7 @@ name = "string_sum"
 crate-type = ["cdylib"]
 
 [dependencies.pyo3]
-version = "0.8.5"
+version = "0.9.0-alpha.1"
 features = ["extension-module"]
 ```
 
@@ -89,7 +89,7 @@ Add `pyo3` to your `Cargo.toml` like this:
 
 ```toml
 [dependencies]
-pyo3 = "0.8.5"
+pyo3 = "0.9.0-alpha.1"
 ```
 
 Example program displaying the value of `sys.version` and the current user name:
diff --git a/pyo3-derive-backend/Cargo.toml b/pyo3-derive-backend/Cargo.toml
index b3b974eb..cf158453 100644
--- a/pyo3-derive-backend/Cargo.toml
+++ b/pyo3-derive-backend/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "pyo3-derive-backend"
-version = "0.8.5"
+version = "0.9.0-alpha.1"
 description = "Code generation for PyO3 package"
 authors = ["PyO3 Project and Contributors <https://github.com/PyO3>"]
 keywords = ["pyo3", "python", "cpython", "ffi"]
diff --git a/pyo3cls/Cargo.toml b/pyo3cls/Cargo.toml
index 19fcaf70..93c19d11 100644
--- a/pyo3cls/Cargo.toml
+++ b/pyo3cls/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "pyo3cls"
-version = "0.8.5"
+version = "0.9.0-alpha.1"
 description = "Proc macros for PyO3 package"
 authors = ["PyO3 Project and Contributors <https://github.com/PyO3>"]
 keywords = ["pyo3", "python", "cpython", "ffi"]
@@ -17,4 +17,4 @@ proc-macro = true
 quote = "1"
 proc-macro2 = "1"
 syn = { version = "1", features = ["full", "extra-traits"] }
-pyo3-derive-backend = { path = "../pyo3-derive-backend", version = "=0.8.5" }
+pyo3-derive-backend = { path = "../pyo3-derive-backend", version = "=0.9.0-alpha.1" }
diff --git a/src/lib.rs b/src/lib.rs
index 0367af54..c670c20c 100755
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -48,7 +48,7 @@
 //! crate-type = ["cdylib"]
 //!
 //! [dependencies.pyo3]
-//! version = "0.8.5"
+//! version = "0.9.0-alpha.1"
 //! features = ["extension-module"]
 //! ```
 //!
@@ -93,7 +93,7 @@
 //!
 //! ```toml
 //! [dependencies]
-//! pyo3 = "0.8.5"
+//! pyo3 = "0.9.0-alpha.1"
 //! ```
 //!
 //! Example program displaying the value of `sys.version`: