diff --git a/CHANGELOG.md b/CHANGELOG.md
index 00af968..5fa5ea8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,13 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.23.0] - unreleased
+
+- Update `prost` dependencies to `v0.12`.
+  See [PR 198].
+
+[PR 198]: https://github.com/prometheus/client_rust/pull/198
+
 ## [0.22.3]
 
 ### Added
diff --git a/Cargo.toml b/Cargo.toml
index 4f78e1e..2c1f889 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "prometheus-client"
-version = "0.22.3"
+version = "0.23.0"
 authors = ["Max Inden <mail@max-inden.de>"]
 edition = "2021"
 description = "Open Metrics client library allowing users to natively instrument applications."
@@ -22,14 +22,14 @@ dtoa = "1.0"
 itoa = "1.0"
 parking_lot = "0.12"
 prometheus-client-derive-encode = { version = "0.4.1", path = "derive-encode" }
-prost = { version = "0.11.0", optional = true }
-prost-types = { version = "0.11.0", optional = true }
+prost = { version = "0.12.0", optional = true }
+prost-types = { version = "0.12.0", optional = true }
 
 [dev-dependencies]
 async-std = { version = "1", features = ["attributes"] }
 criterion = "0.5"
 http-types = "2"
-pyo3 = "0.20"
+pyo3 = "0.21"
 quickcheck = "1"
 rand = "0.8.4"
 tide = "0.16"
@@ -40,7 +40,7 @@ hyper-util = { version = "0.1.3", features = ["tokio"] }
 http-body-util = "0.1.1"
 
 [build-dependencies]
-prost-build = { version = "0.11.0", optional = true }
+prost-build = { version = "0.12.0", optional = true }
 
 [[bench]]
 name = "baseline"
diff --git a/src/encoding/text.rs b/src/encoding/text.rs
index 4281526..bf65aa0 100644
--- a/src/encoding/text.rs
+++ b/src/encoding/text.rs
@@ -1104,7 +1104,7 @@ mod tests {
 
         println!("{:?}", input);
         Python::with_gil(|py| {
-            let parser = PyModule::from_code(
+            let parser = PyModule::from_code_bound(
                 py,
                 r#"
 from prometheus_client.openmetrics.parser import text_string_to_metric_families