diff --git a/Cargo.lock b/Cargo.lock
index 7a1e5382..f828fd42 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3061,7 +3061,7 @@ dependencies = [
  "secp256k1",
  "serde",
  "serde-big-array",
- "sha2 0.8.2",
+ "sha2 0.9.1",
  "spandoc",
  "thiserror",
  "tracing",
diff --git a/zebra-chain/Cargo.toml b/zebra-chain/Cargo.toml
index b6482007..8adf8e05 100644
--- a/zebra-chain/Cargo.toml
+++ b/zebra-chain/Cargo.toml
@@ -25,7 +25,7 @@ ripemd160 = "0.8.0"
 secp256k1 = { version = "0.17.2", features = ["serde"] }
 serde = { version = "1", features = ["serde_derive", "rc"] }
 serde-big-array = "0.3.0"
-sha2 = { version = "0.8.2", features=["compress"] }
+sha2 = { version = "0.9.1", features=["compress"] }
 thiserror = "1"
 x25519-dalek = { version = "1", features = ["serde"] }
 
diff --git a/zebra-chain/src/serialization/sha256d.rs b/zebra-chain/src/serialization/sha256d.rs
index 2c6b511d..4b6acbfe 100644
--- a/zebra-chain/src/serialization/sha256d.rs
+++ b/zebra-chain/src/serialization/sha256d.rs
@@ -13,7 +13,7 @@ pub struct Writer {
 impl Writer {
     /// Consume the Writer and produce the hash result.
     pub fn finish(self) -> [u8; 32] {
-        let result1 = self.hash.result();
+        let result1 = self.hash.finalize();
         let result2 = Sha256::digest(&result1);
         let mut buffer = [0u8; 32];
         buffer[0..32].copy_from_slice(&result2[0..32]);
@@ -23,7 +23,7 @@ impl Writer {
 
 impl Write for Writer {
     fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
-        self.hash.input(buf);
+        self.hash.update(buf);
         Ok(buf.len())
     }
 
diff --git a/zebra-chain/src/sprout/commitment.rs b/zebra-chain/src/sprout/commitment.rs
index 39895e99..379f67a3 100644
--- a/zebra-chain/src/sprout/commitment.rs
+++ b/zebra-chain/src/sprout/commitment.rs
@@ -37,12 +37,12 @@ impl From<Note> for NoteCommitment {
     fn from(note: Note) -> NoteCommitment {
         let leading_byte: u8 = 0xB0;
         let mut hasher = Sha256::default();
-        hasher.input([leading_byte]);
-        hasher.input(note.paying_key);
-        hasher.input(note.value.to_bytes());
-        hasher.input(note.rho);
-        hasher.input(note.rcm);
-        NoteCommitment(hasher.result().into())
+        hasher.update([leading_byte]);
+        hasher.update(note.paying_key);
+        hasher.update(note.value.to_bytes());
+        hasher.update(note.rho);
+        hasher.update(note.rcm);
+        NoteCommitment(hasher.finalize().into())
     }
 }
 
diff --git a/zebra-chain/src/sprout/keys.rs b/zebra-chain/src/sprout/keys.rs
index 033f9778..cc96a260 100644
--- a/zebra-chain/src/sprout/keys.rs
+++ b/zebra-chain/src/sprout/keys.rs
@@ -11,6 +11,7 @@ use std::{fmt, io};
 
 use byteorder::{ByteOrder, LittleEndian};
 use rand_core::{CryptoRng, RngCore};
+use sha2::digest::generic_array::{typenum::U64, GenericArray};
 
 #[cfg(test)]
 use proptest::{array, prelude::*};
@@ -37,17 +38,17 @@ mod sk_magics {
 /// https://zips.z.cash/protocol/protocol.pdf#sproutkeycomponents
 fn prf_addr(x: [u8; 32], t: u8) -> [u8; 32] {
     let mut state = [0u32; 8];
-    let mut block = [0u8; 64];
+    let mut block = GenericArray::<u8, U64>::default();
 
-    block[0..32].copy_from_slice(&x[..]);
+    block.as_mut_slice()[0..32].copy_from_slice(&x[..]);
     // The first four bits –i.e. the most signicant four bits of the
     // first byte– are used to separate distinct uses
     // of SHA256Compress, ensuring that the functions are independent.
-    block[0] |= 0b1100_0000;
+    block.as_mut_slice()[0] |= 0b1100_0000;
 
-    block[32] = t;
+    block.as_mut_slice()[32] = t;
 
-    sha2::compress256(&mut state, &block);
+    sha2::compress256(&mut state, &[block]);
 
     let mut derived_bytes = [0u8; 32];
     LittleEndian::write_u32_into(&state, &mut derived_bytes);
diff --git a/zebra-chain/src/sprout/note/nullifiers.rs b/zebra-chain/src/sprout/note/nullifiers.rs
index 11d0edde..8513739f 100644
--- a/zebra-chain/src/sprout/note/nullifiers.rs
+++ b/zebra-chain/src/sprout/note/nullifiers.rs
@@ -2,6 +2,7 @@
 
 use byteorder::{ByteOrder, LittleEndian};
 use serde::{Deserialize, Serialize};
+use sha2::digest::generic_array::{typenum::U64, GenericArray};
 
 use super::super::keys::SpendingKey;
 
@@ -13,17 +14,17 @@ use super::super::keys::SpendingKey;
 /// https://zips.z.cash/protocol/protocol.pdf#commitmentsandnullifiers
 fn prf_nf(a_sk: [u8; 32], rho: [u8; 32]) -> [u8; 32] {
     let mut state = [0u32; 8];
-    let mut block = [0u8; 64];
+    let mut block = GenericArray::<u8, U64>::default();
 
-    block[0..32].copy_from_slice(&a_sk[..]);
+    block.as_mut_slice()[0..32].copy_from_slice(&a_sk[..]);
     // The first four bits –i.e. the most signicant four bits of the
     // first byte– are used to separate distinct uses
     // of SHA256Compress, ensuring that the functions are independent.
-    block[0] |= 0b1110_0000;
+    block.as_mut_slice()[0] |= 0b1100_0000;
 
-    block[32..].copy_from_slice(&rho[..]);
+    block.as_mut_slice()[32..].copy_from_slice(&rho[..]);
 
-    sha2::compress256(&mut state, &block);
+    sha2::compress256(&mut state, &[block]);
 
     let mut derived_bytes = [0u8; 32];
     LittleEndian::write_u32_into(&state, &mut derived_bytes);
diff --git a/zebra-chain/src/transparent/address.rs b/zebra-chain/src/transparent/address.rs
index 29e0213f..5506f29a 100644
--- a/zebra-chain/src/transparent/address.rs
+++ b/zebra-chain/src/transparent/address.rs
@@ -4,7 +4,7 @@ use std::{fmt, io};
 
 use ripemd160::{Digest, Ripemd160};
 use secp256k1::PublicKey;
-use sha2::Sha256;
+use sha2::{Digest as sha2Digest, Sha256};
 
 #[cfg(test)]
 use proptest::{arbitrary::Arbitrary, collection::vec, prelude::*};