diff --git a/.cargo_vcs_info.json b/.cargo_vcs_info.json
index ffd4f55..724f674 100644
--- a/.cargo_vcs_info.json
+++ b/.cargo_vcs_info.json
@@ -1,5 +1,6 @@
 {
   "git": {
-    "sha1": "7caefa51304e78fd5018cd5d2a03f3b9089cc010"
-  }
-}
+    "sha1": "fc1e3250219170e31cddb8857a276cba7dd08d44"
+  },
+  "path_in_vcs": "futures-core"
+}
\ No newline at end of file
diff --git a/Android.bp b/Android.bp
index 5553a3b..898123d 100644
--- a/Android.bp
+++ b/Android.bp
@@ -42,7 +42,7 @@
     host_supported: true,
     crate_name: "futures_core",
     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 683786a..32fedcb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,17 +11,22 @@
 
 [package]
 edition = "2018"
+rust-version = "1.36"
 name = "futures-core"
-version = "0.3.17"
-authors = ["Alex Crichton <alex@alexcrichton.com>"]
-description = "The core traits and types in for the `futures` library.\n"
+version = "0.3.21"
+description = """
+The core traits and types in for the `futures` library.
+"""
 homepage = "https://rust-lang.github.io/futures-rs"
-documentation = "https://docs.rs/futures-core/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]
 
diff --git a/Cargo.toml.orig b/Cargo.toml.orig
index 29134f2..4a360f8 100644
--- a/Cargo.toml.orig
+++ b/Cargo.toml.orig
@@ -1,12 +1,11 @@
 [package]
 name = "futures-core"
+version = "0.3.21"
 edition = "2018"
-version = "0.3.17"
-authors = ["Alex Crichton <alex@alexcrichton.com>"]
+rust-version = "1.36"
 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-core/0.3"
 description = """
 The core traits and types in for the `futures` library.
 """
diff --git a/METADATA b/METADATA
index dcebdb0..6829297 100644
--- a/METADATA
+++ b/METADATA
@@ -7,13 +7,13 @@
   }
   url {
     type: ARCHIVE
-    value: "https://static.crates.io/crates/futures-core/futures-core-0.3.17.crate"
+    value: "https://static.crates.io/crates/futures-core/futures-core-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..96e0e06
--- /dev/null
+++ b/README.md
@@ -0,0 +1,23 @@
+# futures-core
+
+The core traits and types in for the `futures` library.
+
+## Usage
+
+Add this to your `Cargo.toml`:
+
+```toml
+[dependencies]
+futures-core = "0.3"
+```
+
+The current `futures-core` requires Rust 1.36 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",