diff --git a/src/gadgets/merkle_proofs.rs b/src/gadgets/merkle_proofs.rs
index 94abb0e1..246406b6 100644
--- a/src/gadgets/merkle_proofs.rs
+++ b/src/gadgets/merkle_proofs.rs
@@ -1,30 +1,37 @@
 use crate::circuit_builder::CircuitBuilder;
 use crate::field::field::Field;
+use crate::proof::{Hash, HashTarget};
 use crate::target::Target;
 
 pub struct MerkleProof<F: Field> {
     /// The Merkle digest of each sibling subtree, staying from the bottommost layer.
-    pub siblings: Vec<F>,
+    pub siblings: Vec<Hash<F>>,
 }
 
 pub struct MerkleProofTarget {
     /// The Merkle digest of each sibling subtree, staying from the bottommost layer.
-    pub siblings: Vec<Target>,
+    pub siblings: Vec<HashTarget>,
 }
 
+/// Verifies that the given leaf data is present at the given index in the Merkle tree with the
+/// given root.
 pub(crate) fn verify_merkle_proof<F: Field>(
-    leaf_index: usize,
     leaf_data: Vec<F>,
+    leaf_index: usize,
+    merkle_root: Hash<F>,
     proof: MerkleProof<F>,
 ) {
     todo!()
 }
 
 impl<F: Field> CircuitBuilder<F> {
+    /// Verifies that the given leaf data is present at the given index in the Merkle tree with the
+    /// given root.
     pub(crate) fn verify_merkle_proof(
         &mut self,
-        leaf_index: Target,
         leaf_data: Vec<Target>,
+        leaf_index: Target,
+        merkle_root: HashTarget,
         proof: MerkleProofTarget,
     ) {
         todo!()
diff --git a/src/proof.rs b/src/proof.rs
index 9bfd5843..d25196cb 100644
--- a/src/proof.rs
+++ b/src/proof.rs
@@ -53,6 +53,8 @@ pub struct ProofTarget {
 }
 
 pub struct FriProof<F: Field> {
+    /// A Merkle root for each reduced polynomial in the commit phase.
+    pub commit_phase_merkle_roots: Vec<Hash<F>>,
     /// Merkle proofs for the original purported codewords, i.e. the subject of the LDT.
     pub initial_merkle_proofs: Vec<MerkleProof<F>>,
     /// Merkle proofs for the reduced polynomials that were sent in the commit phase.
@@ -63,6 +65,8 @@ pub struct FriProof<F: Field> {
 
 /// Represents a single FRI query, i.e. a path through the reduction tree.
 pub struct FriProofTarget {
+    /// A Merkle root for each reduced polynomial in the commit phase.
+    pub commit_phase_merkle_roots: Vec<HashTarget>,
     /// Merkle proofs for the original purported codewords, i.e. the subject of the LDT.
     pub initial_merkle_proofs: Vec<MerkleProofTarget>,
     /// Merkle proofs for the reduced polynomials that were sent in the commit phase.