diff --git a/src/fri/recursive_verifier.rs b/src/fri/recursive_verifier.rs
index 5d62d26c..cc3a1ddf 100644
--- a/src/fri/recursive_verifier.rs
+++ b/src/fri/recursive_verifier.rs
@@ -177,6 +177,7 @@ impl<F: Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         x_index_bits: &[Target],
         proof: &FriInitialTreeProofTarget,
         initial_merkle_roots: &[MerkleCapTarget],
+        cap_index: Target,
     ) {
         for (i, ((evals, merkle_proof), root)) in proof
             .evals_proofs
@@ -187,7 +188,13 @@ impl<F: Extendable<D>, const D: usize> CircuitBuilder<F, D> {
             with_context!(
                 self,
                 &format!("verify {}'th initial Merkle proof", i),
-                self.verify_merkle_proof(evals.clone(), x_index_bits, root, merkle_proof)
+                self.verify_merkle_proof_with_cap_index(
+                    evals.clone(),
+                    x_index_bits,
+                    cap_index,
+                    root,
+                    merkle_proof
+                )
             );
         }
     }
@@ -297,6 +304,7 @@ impl<F: Extendable<D>, const D: usize> CircuitBuilder<F, D> {
                 &x_index_bits,
                 &round_proof.initial_trees_proof,
                 initial_merkle_roots,
+                cap_index
             )
         );
         let mut old_x_index_bits = Vec::new();
diff --git a/src/plonk/recursive_verifier.rs b/src/plonk/recursive_verifier.rs
index 0c297c66..fac0ba3a 100644
--- a/src/plonk/recursive_verifier.rs
+++ b/src/plonk/recursive_verifier.rs
@@ -132,6 +132,7 @@ impl<F: Extendable<D>, const D: usize> CircuitBuilder<F, D> {
 #[cfg(test)]
 mod tests {
     use anyhow::Result;
+    use log::info;
 
     use super::*;
     use crate::field::crandall_field::CrandallField;
@@ -425,17 +426,17 @@ mod tests {
         const D: usize = 4;
         let config = CircuitConfig {
             num_wires: 126,
-            num_routed_wires: 33,
+            num_routed_wires: 37,
             security_bits: 128,
             rate_bits: 3,
             num_challenges: 3,
             zero_knowledge: false,
-            cap_height: 2,
+            cap_height: 3,
             fri_config: FriConfig {
                 proof_of_work_bits: 1,
                 reduction_arity_bits: vec![2, 2, 2, 2, 2, 2],
                 num_query_rounds: 40,
-                cap_height: 2,
+                cap_height: 3,
             },
         };
         let (proof_with_pis, vd, cd) = {
@@ -488,6 +489,8 @@ mod tests {
         builder.print_gate_counts(0);
         let data = builder.build();
         let recursive_proof = data.prove(pw)?;
+        let proof_bytes = serde_cbor::to_vec(&recursive_proof).unwrap();
+        info!("Proof length: {} bytes", proof_bytes.len());
         verify(recursive_proof, &data.verifier_only, &data.common)
     }
 }