diff --git a/README.md b/README.md
index 9e518a0..fbefbdf 100644
--- a/README.md
+++ b/README.md
@@ -94,7 +94,7 @@ First, add `pyo3_bindgen` as a **build dependency** to your [`Cargo.toml`](https
 pyo3_bindgen = { version = "0.4" }
 
 [dependencies]
-pyo3 = { version = "0.20", features = ["auto-initialize"] }
+pyo3 = { version = "0.21", features = ["auto-initialize"] }
 ```
 
 Then, create a [`build.rs`](https://doc.rust-lang.org/cargo/reference/build-scripts.html) script in the root of your crate that generates bindings to the selected Python modules. In this example, the bindings are simultaneously generated for the "os", "posixpath", and "sys" Python modules. At the end of the generation process, the Rust bindings are written to `${OUT_DIR}/bindings.rs`.
diff --git a/pyo3_bindgen/src/lib.rs b/pyo3_bindgen/src/lib.rs
index 973d693..ce17ff5 100644
--- a/pyo3_bindgen/src/lib.rs
+++ b/pyo3_bindgen/src/lib.rs
@@ -19,7 +19,7 @@
 //! pyo3_bindgen = { version = "0.4" }
 //!
 //! [dependencies]
-//! pyo3 = { version = "0.20", features = ["auto-initialize"] }
+//! pyo3 = { version = "0.21", features = ["auto-initialize"] }
 //! ```
 //!
 //! Then, create a [`build.rs`](https://doc.rust-lang.org/cargo/reference/build-scripts.html) script in the root of your crate that generates bindings to the selected Python modules. In this example, the bindings are simultaneously generated for the "os", "posixpath", and "sys" Python modules. At the end of the generation process, the Rust bindings are written to `${OUT_DIR}/bindings.rs`.