diff --git a/Cargo.toml b/Cargo.toml
index efe0a6de..21dc48cf 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -84,3 +84,4 @@ debug = true
 [patch.crates-io]
 halo2_gadgets = { git = "https://github.com/zcash/halo2.git", rev = "0c33fa4e6e41464884765c8fb4cefebafd300ca2" }
 halo2_proofs = { git = "https://github.com/zcash/halo2.git", rev = "0c33fa4e6e41464884765c8fb4cefebafd300ca2" }
+incrementalmerkletree = { git = "https://github.com/zcash/incrementalmerkletree.git", rev = "f23e3d89507849a24543121839eea6f40b141aff" }
diff --git a/src/builder.rs b/src/builder.rs
index f85d08a2..4bfdd843 100644
--- a/src/builder.rs
+++ b/src/builder.rs
@@ -590,8 +590,7 @@ impl<V> Bundle<InProgress<Proof, PartiallyAuthorized>, V> {
 #[cfg_attr(docsrs, doc(cfg(feature = "test-dependencies")))]
 pub mod testing {
     use core::fmt::Debug;
-
-    use incrementalmerkletree::{bridgetree::BridgeTree, Frontier, Tree};
+    use incrementalmerkletree::{bridgetree::BridgeTree, Tree};
     use rand::{rngs::StdRng, CryptoRng, SeedableRng};
 
     use proptest::collection::vec;
@@ -666,6 +665,7 @@ pub mod testing {
         (
             n_notes in 1usize..30,
             n_recipients in 1..30,
+
         )
         (
             // generate note values that we're certain won't exceed MAX_NOTE_VALUE in total
@@ -691,14 +691,15 @@ pub mod testing {
                 tree.append(&leaf);
                 let position = tree.witness().expect("tree is not empty");
 
-                let path = MerklePath::from((position, tree.authentication_path(position).expect("we just witnessed the path")));
+                let root = tree.root(0).unwrap();
+                let path = MerklePath::from((position, tree.authentication_path(position, &root).expect("we just witnessed the path")));
                 notes_and_auth_paths.push((*note, path));
             }
 
             ArbitraryBundleInputs {
                 rng: StdRng::from_seed(rng_seed),
                 sk,
-                anchor: tree.root().into(),
+                anchor: tree.root(0).unwrap().into(),
                 notes: notes_and_auth_paths,
                 recipient_amounts
             }
diff --git a/src/tree.rs b/src/tree.rs
index 92ca0344..2dfd4fae 100644
--- a/src/tree.rs
+++ b/src/tree.rs
@@ -284,14 +284,15 @@ pub mod testing {
             let position = tree.witness().expect("tree is not empty");
             assert_eq!(position, i.into());
 
-            assert_eq!(tree.root().0, pallas::Base::from_repr(tv.root).unwrap());
+            let root = tree.root(0).unwrap();
+            assert_eq!(root.0, pallas::Base::from_repr(tv.root).unwrap());
 
             // Check paths for all leaves up to this point. The test vectors include paths
             // for not-yet-appended leaves (using UNCOMMITTED_ORCHARD as the leaf value),
             // but BridgeTree doesn't encode these.
             for j in 0..=i {
                 assert_eq!(
-                    tree.authentication_path(j.try_into().unwrap()),
+                    tree.authentication_path(j.try_into().unwrap(), &root),
                     Some(
                         tv.paths[j]
                             .iter()
diff --git a/tests/builder.rs b/tests/builder.rs
index ee1656f0..35c53976 100644
--- a/tests/builder.rs
+++ b/tests/builder.rs
@@ -1,4 +1,4 @@
-use incrementalmerkletree::{bridgetree::BridgeTree, Frontier, Hashable, Tree};
+use incrementalmerkletree::{bridgetree::BridgeTree, Hashable, Tree};
 use orchard::{
     builder::Builder,
     bundle::{Authorized, Flags},
@@ -73,12 +73,13 @@ fn bundle_chain() {
         let mut tree = BridgeTree::<MerkleHashOrchard, 32>::new(0);
         tree.append(&leaf);
         let position = tree.witness().unwrap();
-        let auth_path = tree.authentication_path(position).unwrap();
+        let root = tree.root(0).unwrap();
+        let auth_path = tree.authentication_path(position, &root).unwrap();
         let merkle_path = MerklePath::from_parts(
             u64::from(position).try_into().unwrap(),
             auth_path[..].try_into().unwrap(),
         );
-        let anchor = tree.root().into();
+        let anchor = root.into();
         assert_eq!(anchor, merkle_path.root(cmx));
 
         let mut builder = Builder::new(Flags::from_parts(true, true), anchor);