diff --git a/.cargo_vcs_info.json b/.cargo_vcs_info.json
index ffd4f55..deccf0d 100644
--- a/.cargo_vcs_info.json
+++ b/.cargo_vcs_info.json
@@ -1,5 +1,6 @@
 {
   "git": {
-    "sha1": "7caefa51304e78fd5018cd5d2a03f3b9089cc010"
-  }
-}
+    "sha1": "fc1e3250219170e31cddb8857a276cba7dd08d44"
+  },
+  "path_in_vcs": "futures-channel"
+}
\ No newline at end of file
diff --git a/Android.bp b/Android.bp
index 582a0ff..c7bc955 100644
--- a/Android.bp
+++ b/Android.bp
@@ -46,7 +46,7 @@
     host_supported: true,
     crate_name: "futures_channel",
     cargo_env_compat: true,
-    cargo_pkg_version: "0.3.17",
+    cargo_pkg_version: "0.3.21",
     srcs: ["src/lib.rs"],
     edition: "2018",
     features: [
diff --git a/Cargo.toml b/Cargo.toml
index bea8d51..d0a13f6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,23 +11,29 @@
 
 [package]
 edition = "2018"
+rust-version = "1.45"
 name = "futures-channel"
-version = "0.3.17"
-authors = ["Alex Crichton <alex@alexcrichton.com>"]
-description = "Channels for asynchronous communication using futures-rs.\n"
+version = "0.3.21"
+description = """
+Channels for asynchronous communication using futures-rs.
+"""
 homepage = "https://rust-lang.github.io/futures-rs"
-documentation = "https://docs.rs/futures-channel/0.3"
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/rust-lang/futures-rs"
+
 [package.metadata.docs.rs]
 all-features = true
-rustdoc-args = ["--cfg", "docsrs"]
+rustdoc-args = [
+    "--cfg",
+    "docsrs",
+]
+
 [dependencies.futures-core]
-version = "0.3.17"
+version = "0.3.21"
 default-features = false
 
 [dependencies.futures-sink]
-version = "0.3.17"
+version = "0.3.21"
 optional = true
 default-features = false
 
@@ -38,5 +44,8 @@
 cfg-target-has-atomic = []
 default = ["std"]
 sink = ["futures-sink"]
-std = ["alloc", "futures-core/std"]
+std = [
+    "alloc",
+    "futures-core/std",
+]
 unstable = []
diff --git a/Cargo.toml.orig b/Cargo.toml.orig
index 6bd240c..f356eab 100644
--- a/Cargo.toml.orig
+++ b/Cargo.toml.orig
@@ -1,12 +1,11 @@
 [package]
 name = "futures-channel"
+version = "0.3.21"
 edition = "2018"
-version = "0.3.17"
-authors = ["Alex Crichton <alex@alexcrichton.com>"]
+rust-version = "1.45"
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/rust-lang/futures-rs"
 homepage = "https://rust-lang.github.io/futures-rs"
-documentation = "https://docs.rs/futures-channel/0.3"
 description = """
 Channels for asynchronous communication using futures-rs.
 """
@@ -23,8 +22,8 @@
 cfg-target-has-atomic = []
 
 [dependencies]
-futures-core = { path = "../futures-core", version = "0.3.17", default-features = false }
-futures-sink = { path = "../futures-sink", version = "0.3.17", default-features = false, optional = true }
+futures-core = { path = "../futures-core", version = "0.3.21", default-features = false }
+futures-sink = { path = "../futures-sink", version = "0.3.21", default-features = false, optional = true }
 
 [dev-dependencies]
 futures = { path = "../futures", default-features = true }
diff --git a/METADATA b/METADATA
index fc42915..29bf06e 100644
--- a/METADATA
+++ b/METADATA
@@ -7,13 +7,13 @@
   }
   url {
     type: ARCHIVE
-    value: "https://static.crates.io/crates/futures-channel/futures-channel-0.3.17.crate"
+    value: "https://static.crates.io/crates/futures-channel/futures-channel-0.3.21.crate"
   }
-  version: "0.3.17"
+  version: "0.3.21"
   license_type: NOTICE
   last_upgrade_date {
-    year: 2021
-    month: 9
-    day: 22
+    year: 2022
+    month: 3
+    day: 1
   }
 }
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..3287be9
--- /dev/null
+++ b/README.md
@@ -0,0 +1,23 @@
+# futures-channel
+
+Channels for asynchronous communication using futures-rs.
+
+## Usage
+
+Add this to your `Cargo.toml`:
+
+```toml
+[dependencies]
+futures-channel = "0.3"
+```
+
+The current `futures-channel` requires Rust 1.45 or later.
+
+## License
+
+Licensed under either of [Apache License, Version 2.0](LICENSE-APACHE) or
+[MIT license](LICENSE-MIT) at your option.
+
+Unless you explicitly state otherwise, any contribution intentionally submitted
+for inclusion in the work by you, as defined in the Apache-2.0 license, shall
+be dual licensed as above, without any additional terms or conditions.
diff --git a/build.rs b/build.rs
index 07b50bd..05e0496 100644
--- a/build.rs
+++ b/build.rs
@@ -1,9 +1,3 @@
-#![warn(rust_2018_idioms, single_use_lifetimes)]
-
-use std::env;
-
-include!("no_atomic_cas.rs");
-
 // The rustc-cfg listed below are considered public API, but it is *unstable*
 // and outside of the normal semver guarantees:
 //
@@ -13,10 +7,15 @@
 //      need to enable it manually when building for custom targets or using
 //      non-cargo build systems that don't run the build script.
 //
-// With the exceptions mentioned above, the rustc-cfg strings below are
-// *not* public API. Please let us know by opening a GitHub issue if your build
-// environment requires some way to enable these cfgs other than by executing
-// our build script.
+// With the exceptions mentioned above, the rustc-cfg emitted by the build
+// script are *not* public API.
+
+#![warn(rust_2018_idioms, single_use_lifetimes)]
+
+use std::env;
+
+include!("no_atomic_cas.rs");
+
 fn main() {
     let target = match env::var("TARGET") {
         Ok(target) => target,
@@ -34,7 +33,7 @@
     // `cfg(target_has_atomic = "ptr")` as true when the build script doesn't
     // run. This is needed for compatibility with non-cargo build systems that
     // don't run the build script.
-    if NO_ATOMIC_CAS_TARGETS.contains(&&*target) {
+    if NO_ATOMIC_CAS.contains(&&*target) {
         println!("cargo:rustc-cfg=futures_no_atomic_cas");
     }
 
diff --git a/no_atomic_cas.rs b/no_atomic_cas.rs
index 4708bf8..9b05d4b 100644
--- a/no_atomic_cas.rs
+++ b/no_atomic_cas.rs
@@ -1,7 +1,7 @@
 // This file is @generated by no_atomic_cas.sh.
 // It is not intended for manual editing.
 
-const NO_ATOMIC_CAS_TARGETS: &[&str] = &[
+const NO_ATOMIC_CAS: &[&str] = &[
     "avr-unknown-gnu-atmega328",
     "bpfeb-unknown-none",
     "bpfel-unknown-none",
diff --git a/tests/mpsc-close.rs b/tests/mpsc-close.rs
index 81203d3..1a14067 100644
--- a/tests/mpsc-close.rs
+++ b/tests/mpsc-close.rs
@@ -147,6 +147,7 @@
 
 // Stress test that `try_send()`s occurring concurrently with receiver
 // close/drops don't appear as successful sends.
+#[cfg_attr(miri, ignore)] // Miri is too slow
 #[test]
 fn stress_try_send_as_receiver_closes() {
     const AMT: usize = 10000;
diff --git a/tests/mpsc.rs b/tests/mpsc.rs
index 88cdef1..da0899d 100644
--- a/tests/mpsc.rs
+++ b/tests/mpsc.rs
@@ -200,6 +200,9 @@
 
 #[test]
 fn stress_shared_unbounded() {
+    #[cfg(miri)]
+    const AMT: u32 = 100;
+    #[cfg(not(miri))]
     const AMT: u32 = 10000;
     const NTHREADS: u32 = 8;
     let (tx, rx) = mpsc::unbounded::<i32>();
@@ -229,6 +232,9 @@
 
 #[test]
 fn stress_shared_bounded_hard() {
+    #[cfg(miri)]
+    const AMT: u32 = 100;
+    #[cfg(not(miri))]
     const AMT: u32 = 10000;
     const NTHREADS: u32 = 8;
     let (tx, rx) = mpsc::channel::<i32>(0);
@@ -259,6 +265,9 @@
 #[allow(clippy::same_item_push)]
 #[test]
 fn stress_receiver_multi_task_bounded_hard() {
+    #[cfg(miri)]
+    const AMT: usize = 100;
+    #[cfg(not(miri))]
     const AMT: usize = 10_000;
     const NTHREADS: u32 = 2;
 
@@ -327,6 +336,11 @@
 /// after sender dropped.
 #[test]
 fn stress_drop_sender() {
+    #[cfg(miri)]
+    const ITER: usize = 100;
+    #[cfg(not(miri))]
+    const ITER: usize = 10000;
+
     fn list() -> impl Stream<Item = i32> {
         let (tx, rx) = mpsc::channel(1);
         thread::spawn(move || {
@@ -335,7 +349,7 @@
         rx
     }
 
-    for _ in 0..10000 {
+    for _ in 0..ITER {
         let v: Vec<_> = block_on(list().collect());
         assert_eq!(v, vec![1, 2, 3]);
     }
@@ -380,9 +394,12 @@
     }
 }
 
+#[cfg_attr(miri, ignore)] // Miri is too slow
 #[test]
 fn stress_close_receiver() {
-    for _ in 0..10000 {
+    const ITER: usize = 10000;
+
+    for _ in 0..ITER {
         stress_close_receiver_iter();
     }
 }
@@ -397,6 +414,9 @@
 #[allow(clippy::same_item_push)]
 #[test]
 fn stress_poll_ready() {
+    #[cfg(miri)]
+    const AMT: u32 = 100;
+    #[cfg(not(miri))]
     const AMT: u32 = 1000;
     const NTHREADS: u32 = 8;
 
@@ -424,6 +444,7 @@
     stress(16);
 }
 
+#[cfg_attr(miri, ignore)] // Miri is too slow
 #[test]
 fn try_send_1() {
     const N: usize = 3000;
diff --git a/tests/oneshot.rs b/tests/oneshot.rs
index 979cd8a..c9f5508 100644
--- a/tests/oneshot.rs
+++ b/tests/oneshot.rs
@@ -35,6 +35,11 @@
 
 #[test]
 fn cancel_lots() {
+    #[cfg(miri)]
+    const N: usize = 100;
+    #[cfg(not(miri))]
+    const N: usize = 20000;
+
     let (tx, rx) = mpsc::channel::<(Sender<_>, mpsc::Sender<_>)>();
     let t = thread::spawn(move || {
         for (mut tx, tx2) in rx {
@@ -43,7 +48,7 @@
         }
     });
 
-    for _ in 0..20000 {
+    for _ in 0..N {
         let (otx, orx) = oneshot::channel::<u32>();
         let (tx2, rx2) = mpsc::channel();
         tx.send((otx, tx2)).unwrap();
@@ -101,6 +106,11 @@
 
 #[test]
 fn cancel_sends() {
+    #[cfg(miri)]
+    const N: usize = 100;
+    #[cfg(not(miri))]
+    const N: usize = 20000;
+
     let (tx, rx) = mpsc::channel::<Sender<_>>();
     let t = thread::spawn(move || {
         for otx in rx {
@@ -108,7 +118,7 @@
         }
     });
 
-    for _ in 0..20000 {
+    for _ in 0..N {
         let (otx, mut orx) = oneshot::channel::<u32>();
         tx.send(otx).unwrap();