diff --git a/validator_client/src/attestation_service.rs b/validator_client/src/attestation_service.rs
index c172399fd3..4213edc439 100644
--- a/validator_client/src/attestation_service.rs
+++ b/validator_client/src/attestation_service.rs
@@ -371,7 +371,8 @@ impl<T: SlotClock + 'static, E: EthSpec> AttestationService<T, E> {
 
             // Ensure that the attestation matches the duties.
             #[allow(clippy::suspicious_operation_groupings)]
-            if duty.slot != attestation_data.slot || (fork_name < ForkName::Electra && duty.committee_index != attestation_data.index)
+            if duty.slot != attestation_data.slot
+                || (fork_name < ForkName::Electra && duty.committee_index != attestation_data.index)
             {
                 crit!(
                     log,
@@ -553,6 +554,12 @@ impl<T: SlotClock + 'static, E: EthSpec> AttestationService<T, E> {
             .await
             .map_err(|e| e.to_string())?;
 
+        let fork_name = self
+            .context
+            .eth2_config
+            .spec
+            .fork_name_at_slot::<E>(attestation_data.slot);
+
         // Create futures to produce the signed aggregated attestations.
         let signing_futures = validator_duties.iter().map(|duty_and_proof| async move {
             let duty = &duty_and_proof.duty;
@@ -561,7 +568,9 @@ impl<T: SlotClock + 'static, E: EthSpec> AttestationService<T, E> {
             let slot = attestation_data.slot;
             let committee_index = attestation_data.index;
 
-            if duty.slot != slot || duty.committee_index != committee_index {
+            if duty.slot != slot
+                || (fork_name < ForkName::Electra && duty.committee_index != committee_index)
+            {
                 crit!(log, "Inconsistent validator duties during signing");
                 return None;
             }