diff --git a/sha2/Cargo.toml b/sha2/Cargo.toml
index e8694817..0c858aad 100644
--- a/sha2/Cargo.toml
+++ b/sha2/Cargo.toml
@@ -25,6 +25,7 @@ hex-literal = "0.1"
 default = ["std"]
 std = ["digest/std"]
 asm = ["sha2-asm"]
+compress = []
 
 # TODO: Remove this feature once is_aarch64_feature_detected!() is stabilised.
 # Only used on AArch64 Linux systems, when built without the crypto target_feature.
diff --git a/sha2/src/lib.rs b/sha2/src/lib.rs
index 04b9f5cf..1730feda 100644
--- a/sha2/src/lib.rs
+++ b/sha2/src/lib.rs
@@ -55,40 +55,59 @@
 //! [1]: https://en.wikipedia.org/wiki/SHA-2
 //! [2]: https://github.com/RustCrypto/hashes
 #![no_std]
-#![doc(html_logo_url =
-    "https://raw.githubusercontent.com/RustCrypto/meta/master/logo_small.png")]
+#![doc(html_logo_url = "https://raw.githubusercontent.com/RustCrypto/meta/master/logo_small.png")]
 
 // Give relevant error messages if the user tries to enable AArch64 asm on unsupported platforms.
-#[cfg(all(feature = "asm-aarch64", target_arch = "aarch64", not(target_os = "linux")))]
+#[cfg(all(
+    feature = "asm-aarch64",
+    target_arch = "aarch64",
+    not(target_os = "linux")
+))]
 compile_error!("Your OS isn’t yet supported for runtime-checking of AArch64 features.");
 #[cfg(all(feature = "asm-aarch64", not(target_arch = "aarch64")))]
 compile_error!("Enable the \"asm\" feature instead of \"asm-aarch64\" on non-AArch64 systems.");
-#[cfg(all(feature = "asm-aarch64", target_arch = "aarch64", target_feature = "crypto"))]
+#[cfg(all(
+    feature = "asm-aarch64",
+    target_arch = "aarch64",
+    target_feature = "crypto"
+))]
 compile_error!("Enable the \"asm\" feature instead of \"asm-aarch64\" when building for AArch64 systems with crypto extensions.");
-#[cfg(all(not(feature = "asm-aarch64"), feature = "asm", target_arch = "aarch64", not(target_feature = "crypto"), target_os = "linux"))]
+#[cfg(all(
+    not(feature = "asm-aarch64"),
+    feature = "asm",
+    target_arch = "aarch64",
+    not(target_feature = "crypto"),
+    target_os = "linux"
+))]
 compile_error!("Enable the \"asm-aarch64\" feature on AArch64 if you want to use asm detected at runtime, or build with the crypto extensions support, for instance with RUSTFLAGS='-C target-cpu=native' on a compatible CPU.");
 
 extern crate block_buffer;
 extern crate fake_simd as simd;
-#[macro_use] extern crate opaque_debug;
-#[macro_use] pub extern crate digest;
+#[macro_use]
+extern crate opaque_debug;
+#[macro_use]
+pub extern crate digest;
+#[cfg(feature = "asm-aarch64")]
+extern crate libc;
 #[cfg(feature = "asm")]
 extern crate sha2_asm;
 #[cfg(feature = "std")]
 extern crate std;
-#[cfg(feature = "asm-aarch64")]
-extern crate libc;
 
-mod consts;
-#[cfg(any(not(feature = "asm"), feature = "asm-aarch64"))]
-mod sha256_utils;
-#[cfg(any(not(feature = "asm"), target_arch = "aarch64"))]
-mod sha512_utils;
 #[cfg(feature = "asm-aarch64")]
 mod aarch64;
+mod consts;
 mod sha256;
+#[cfg(any(not(feature = "asm"), feature = "asm-aarch64", feature = "compress"))]
+mod sha256_utils;
 mod sha512;
+#[cfg(any(not(feature = "asm"), target_arch = "aarch64", feature = "compress"))]
+mod sha512_utils;
 
 pub use digest::Digest;
-pub use sha256::{Sha256, Sha224};
-pub use sha512::{Sha512, Sha384, Sha512Trunc224, Sha512Trunc256};
+pub use sha256::{Sha224, Sha256};
+#[cfg(feature = "compress")]
+pub use sha256_utils::compress256;
+pub use sha512::{Sha384, Sha512, Sha512Trunc224, Sha512Trunc256};
+#[cfg(feature = "compress")]
+pub use sha512_utils::compress512;