diff --git a/CHANGELOG.md b/CHANGELOG.md
index 05bdffc5..7c9bb82a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,14 @@ 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).
 
+## [0.17.0] - unreleased
+
+### Changed
+
+- Updates to Rust 2021 Edition. See [PR 65].
+
+[PR 65]: https://github.com/prometheus/client_rust/pull/65
+
 ## [0.16.0]
 
 ### Changed
diff --git a/Cargo.toml b/Cargo.toml
index ec709949..71b0af66 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,8 +1,8 @@
 [package]
 name = "prometheus-client"
-version = "0.16.0"
+version = "0.17.0"
 authors = ["Max Inden <mail@max-inden.de>"]
-edition = "2018"
+edition = "2021"
 description = "Open Metrics client library allowing users to natively instrument applications."
 license = "Apache-2.0 OR MIT"
 keywords = ["openmetrics", "prometheus", "metrics", "instrumentation", "monitoring"]
@@ -17,7 +17,7 @@ members = ["derive-text-encode"]
 dtoa = "1.0"
 itoa = "1.0"
 owning_ref = "0.4"
-prometheus-client-derive-text-encode = { version = "0.2.0", path = "derive-text-encode" }
+prometheus-client-derive-text-encode = { version = "0.3.0", path = "derive-text-encode" }
 prost = "0.9.0"
 prost-types = "0.9.0"
 
diff --git a/derive-text-encode/Cargo.toml b/derive-text-encode/Cargo.toml
index 8bb06f1d..f243c24e 100644
--- a/derive-text-encode/Cargo.toml
+++ b/derive-text-encode/Cargo.toml
@@ -1,8 +1,8 @@
 [package]
 name = "prometheus-client-derive-text-encode"
-version = "0.2.0"
+version = "0.3.0"
 authors = ["Max Inden <mail@max-inden.de>"]
-edition = "2018"
+edition = "2021"
 description = "Auxiliary crate to derive text Encode trait from prometheus-client."
 license = "Apache-2.0 OR MIT"
 repository = "https://github.com/prometheus/client_rust"
diff --git a/src/metrics/family.rs b/src/metrics/family.rs
index 7d5d0e59..1610881b 100644
--- a/src/metrics/family.rs
+++ b/src/metrics/family.rs
@@ -144,9 +144,9 @@ pub trait MetricConstructor<M> {
 /// ```
 /// # use prometheus_client::metrics::family::{Family};
 /// # use prometheus_client::metrics::histogram::Histogram;
-/// let custom_buckets = vec![0.0, 10.0, 100.0];
+/// let custom_buckets = [0.0, 10.0, 100.0];
 /// let metric = Family::<(), Histogram, _>::new_with_constructor(|| {
-///     Histogram::new(custom_buckets.clone().into_iter())
+///     Histogram::new(custom_buckets.into_iter())
 /// });
 /// # metric.get_or_create(&());
 /// ```
diff --git a/src/metrics/histogram.rs b/src/metrics/histogram.rs
index e17799cf..3f2ae9ff 100644
--- a/src/metrics/histogram.rs
+++ b/src/metrics/histogram.rs
@@ -23,9 +23,10 @@ use std::sync::{Arc, Mutex, MutexGuard};
 /// ```
 /// # use prometheus_client::metrics::histogram::Histogram;
 /// // Default values from go client(https://github.com/prometheus/client_golang/blob/5d584e2717ef525673736d72cd1d12e304f243d7/prometheus/histogram.go#L68)
-/// let histogram = Histogram::new(IntoIterator::into_iter([
+/// let custom_buckets = [
 ///    0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1.0, 2.5, 5.0, 10.0,
-/// ]));
+/// ];
+/// let histogram = Histogram::new(custom_buckets.into_iter());
 /// histogram.observe(4.2);
 /// ```
 // TODO: Consider using atomics. See