diff --git a/Cargo.toml b/Cargo.toml
index 64d9dbb786a..c3518fdf1e0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -74,7 +74,7 @@ libc = { version = "0.2.22", default-features = false }
 # Emscripten does not support 128-bit integers, which are used by ChaCha code.
 # We work around this by using a different RNG.
 [target.'cfg(not(target_os = "emscripten"))'.dependencies]
-rand_chacha = { path = "rand_chacha", version = "0.2" }
+rand_chacha = { path = "rand_chacha", version = "0.2.1" }
 [target.'cfg(target_os = "emscripten")'.dependencies]
 rand_hc = { path = "rand_hc", version = "0.2" }
 
diff --git a/rand_chacha/CHANGELOG.md b/rand_chacha/CHANGELOG.md
index dbf91f9df0d..d242f972606 100644
--- a/rand_chacha/CHANGELOG.md
+++ b/rand_chacha/CHANGELOG.md
@@ -4,6 +4,9 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.2.1] - 2019-07-22
+- Force enable the `simd` feature of `c2-chacha` (#845)
+
 ## [0.2.0] - 2019-06-06
 - Rewrite based on the much faster `c2-chacha` crate (#789)
 
diff --git a/rand_chacha/Cargo.toml b/rand_chacha/Cargo.toml
index 90163a7c93f..9d6989b0fb3 100644
--- a/rand_chacha/Cargo.toml
+++ b/rand_chacha/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "rand_chacha"
-version = "0.2.0"
+version = "0.2.1"
 authors = ["The Rand Project Developers", "The Rust Project Developers", "The CryptoCorrosion Contributors"]
 license = "MIT/Apache-2.0"
 readme = "README.md"
@@ -20,9 +20,9 @@ appveyor = { repository = "rust-random/rand" }
 
 [dependencies]
 rand_core = { path = "../rand_core", version = "0.5" }
-c2-chacha = { version = "0.2.2", default-features = false }
+c2-chacha = { version = "0.2.2", default-features = false, features = ["simd"] }
 
 [features]
 default = ["std", "simd"]
 std = ["c2-chacha/std"]
-simd = ["c2-chacha/simd"]
+simd = [] # deprecated
diff --git a/rand_chacha/README.md b/rand_chacha/README.md
index c15611ee4c3..69a0ce7cf2a 100644
--- a/rand_chacha/README.md
+++ b/rand_chacha/README.md
@@ -35,8 +35,9 @@ Links:
 
 ## Crate Features
 
-`rand_chacha` is `no_std` compatible. It does not require any functionality
-outside of the `core` lib, thus there are no features to configure.
+`rand_chacha` is `no_std` compatible when disabling default features; the `std`
+feature can be explicitly required to re-enable `std` support. Using `std`
+allows detection of CPU features and thus better optimisation.
 
 
 # License