diff --git a/CHANGELOG.md b/CHANGELOG.md
index 26792b0cd..412046ab8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,12 +6,18 @@ and this project adheres to Rust's notion of
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+
+## [0.9.0] - 2024-08-12
+
 ### Added
 - `orchard::keys::SpendValidatingKey::{from_bytes, to_bytes}` behind the
   `unstable-frost` feature flag. These are temporary APIs exposed for development
   purposes, and will be replaced by type-safe FROST APIs once ZIP 312 key
   generation is specified (https://github.com/zcash/zips/pull/883).
 
+### Changed
+- Migrated to `incrementalmerkletree 0.6`, `bridgetree 0.5`.
+
 ## [0.8.0] - 2024-03-25
 
 ### Added
diff --git a/Cargo.lock b/Cargo.lock
index 983510038..d72b20fab 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -199,9 +199,9 @@ dependencies = [
 
 [[package]]
 name = "bridgetree"
-version = "0.4.0"
+version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fbfcb6c5a091e80cb3d3b0c1a7f126af4631cd5065b1f9929b139f1be8f3fb62"
+checksum = "f62227647af796dd9f1637da0392676a2e200973b817b082fc9be89bf93ddd74"
 dependencies = [
  "incrementalmerkletree",
 ]
@@ -1087,12 +1087,14 @@ dependencies = [
 
 [[package]]
 name = "incrementalmerkletree"
-version = "0.5.0"
+version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "361c467824d4d9d4f284be4b2608800839419dccc4d4608f28345237fe354623"
+checksum = "75346da3bd8e3d8891d02508245ed2df34447ca6637e343829f8d08986e9cde2"
 dependencies = [
  "either",
  "proptest",
+ "rand",
+ "rand_core",
 ]
 
 [[package]]
@@ -1412,7 +1414,7 @@ checksum = "624a8340c38c1b80fd549087862da4ba43e08858af025b236e509b6649fc13d5"
 
 [[package]]
 name = "orchard"
-version = "0.8.0"
+version = "0.9.0"
 dependencies = [
  "aes",
  "bitvec",
diff --git a/Cargo.toml b/Cargo.toml
index 3267f13f1..be9189610 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "orchard"
-version = "0.8.0"
+version = "0.9.0"
 authors = [
     "Sean Bowe <sean@electriccoin.co>",
     "Jack Grigg <jack@electriccoin.co>",
@@ -42,7 +42,7 @@ nonempty = "0.7"
 serde = { version = "1.0", features = ["derive"] }
 subtle = "2.3"
 zcash_note_encryption = "0.4"
-incrementalmerkletree = "0.5"
+incrementalmerkletree = "0.6"
 zcash_spec = "0.1"
 zip32 = "0.1"
 visibility = "0.1.0"
@@ -55,13 +55,13 @@ image = { version = "0.24", optional = true }
 plotters = { version = "0.3.0", optional = true }
 
 [dev-dependencies]
-bridgetree = "0.4"
+bridgetree = "0.5"
 criterion = "0.4" # 0.5 depends on clap 4 which has MSRV 1.70
 halo2_gadgets = { version = "0.3", features = ["test-dependencies"] }
 hex = "0.4"
 proptest = "1.0.0"
 zcash_note_encryption = { version = "0.4", features = ["pre-zip-212"] }
-incrementalmerkletree = { version = "0.5", features = ["test-dependencies"] }
+incrementalmerkletree = { version = "0.6", features = ["test-dependencies"] }
 
 [target.'cfg(unix)'.dev-dependencies]
 inferno = { version = "0.11", default-features = false, features = ["multithreaded", "nameattr"] }
diff --git a/src/constants.rs b/src/constants.rs
index 8a9b76f23..b64d114f5 100644
--- a/src/constants.rs
+++ b/src/constants.rs
@@ -3,7 +3,7 @@ pub mod fixed_bases;
 pub mod sinsemilla;
 pub mod util;
 
-pub use fixed_bases::{NullifierK, OrchardFixedBases, OrchardFixedBasesFull, ValueCommitV, H};
+pub use fixed_bases::{NullifierK, OrchardFixedBases, OrchardFixedBasesFull, ValueCommitV};
 pub use sinsemilla::{OrchardCommitDomains, OrchardHashDomains};
 
 /// $\mathsf{MerkleDepth^{Orchard}}$