diff --git a/src/gates/gmimc.rs b/src/gates/gmimc.rs
index 73fcc190..311ba841 100644
--- a/src/gates/gmimc.rs
+++ b/src/gates/gmimc.rs
@@ -367,9 +367,9 @@ mod tests {
         generate_partial_witness(
             &mut witness,
             &generators,
-            130,
-            100,
-            100,
+            gate.num_wires(),
+            1,
+            1,
             &mut TimingTree::default(),
         );
 
diff --git a/src/iop/challenger.rs b/src/iop/challenger.rs
index 886fb09e..72314048 100644
--- a/src/iop/challenger.rs
+++ b/src/iop/challenger.rs
@@ -399,7 +399,7 @@ mod tests {
             num_routed_wires: 27,
             ..CircuitConfig::default()
         };
-        let mut builder = CircuitBuilder::<F, 4>::new(config);
+        let mut builder = CircuitBuilder::<F, 4>::new(config.clone());
         let mut recursive_challenger = RecursiveChallenger::new(&mut builder);
         let mut recursive_outputs_per_round: Vec<Vec<Target>> = Vec::new();
         for (r, inputs) in inputs_per_round.iter().enumerate() {
@@ -413,9 +413,9 @@ mod tests {
         generate_partial_witness(
             &mut witness,
             &circuit.prover_only.generators,
-            130,
-            1000,
-            1000,
+            config.num_wires,
+            circuit.common.degree(),
+            circuit.prover_only.num_virtual_targets,
             &mut TimingTree::default(),
         );
         let recursive_output_values_per_round: Vec<Vec<F>> = recursive_outputs_per_round
diff --git a/src/plonk/circuit_builder.rs b/src/plonk/circuit_builder.rs
index 13e57e2d..f4eaa881 100644
--- a/src/plonk/circuit_builder.rs
+++ b/src/plonk/circuit_builder.rs
@@ -576,7 +576,7 @@ impl<F: Extendable<D>, const D: usize> CircuitBuilder<F, D> {
             gate_instances: self.gate_instances,
             public_inputs: self.public_inputs,
             marked_targets: self.marked_targets,
-            max_virtual_target_index: self.virtual_target_index,
+            num_virtual_targets: self.virtual_target_index,
         };
 
         // The HashSet of gates will have a non-deterministic order. When converting to a Vec, we
diff --git a/src/plonk/circuit_data.rs b/src/plonk/circuit_data.rs
index 4c551e38..48ec13be 100644
--- a/src/plonk/circuit_data.rs
+++ b/src/plonk/circuit_data.rs
@@ -136,7 +136,8 @@ pub(crate) struct ProverOnlyCircuitData<F: Extendable<D>, const D: usize> {
     pub public_inputs: Vec<Target>,
     /// A vector of marked targets. The values assigned to these targets will be displayed by the prover.
     pub marked_targets: Vec<MarkedTargets<D>>,
-    pub max_virtual_target_index: usize,
+    /// Number of virtual targets used in the circuit.
+    pub num_virtual_targets: usize,
 }
 
 /// Circuit data required by the verifier, but not the prover.
diff --git a/src/plonk/prover.rs b/src/plonk/prover.rs
index 42e66372..de85d94b 100644
--- a/src/plonk/prover.rs
+++ b/src/plonk/prover.rs
@@ -42,7 +42,7 @@ pub(crate) fn prove<F: Extendable<D>, const D: usize>(
             &prover_data.generators,
             config.num_wires,
             degree,
-            prover_data.max_virtual_target_index,
+            prover_data.num_virtual_targets,
             &mut timing
         )
     );