diff --git a/ethereum/spec/src/main/java/tech/pegasys/teku/spec/datastructures/operations/AttestationSchema.java b/ethereum/spec/src/main/java/tech/pegasys/teku/spec/datastructures/operations/AttestationSchema.java
index 4dde0a0efae..f3b45e20c0f 100644
--- a/ethereum/spec/src/main/java/tech/pegasys/teku/spec/datastructures/operations/AttestationSchema.java
+++ b/ethereum/spec/src/main/java/tech/pegasys/teku/spec/datastructures/operations/AttestationSchema.java
@@ -41,9 +41,9 @@ default SszBitlist createEmptyAggregationBits() {
     return bitsSchema.ofBits(Math.toIntExact(bitsSchema.getMaxLength()));
   }
 
-  default SszBitlist createAggregationBitsOf(final int... indices) {
+  default SszBitlist createAggregationBitsOf(final int size, final int... indices) {
     final SszBitlistSchema<?> bitsSchema = getAggregationBitsSchema();
-    return bitsSchema.ofBits(Math.toIntExact(bitsSchema.getMaxLength()), indices);
+    return bitsSchema.ofBits(size, indices);
   }
 
   default Optional<SszBitvector> createEmptyCommitteeBits() {
diff --git a/ethereum/spec/src/main/java/tech/pegasys/teku/spec/logic/versions/electra/util/AttestationUtilElectra.java b/ethereum/spec/src/main/java/tech/pegasys/teku/spec/logic/versions/electra/util/AttestationUtilElectra.java
index ed17d20c082..c248a7abb12 100644
--- a/ethereum/spec/src/main/java/tech/pegasys/teku/spec/logic/versions/electra/util/AttestationUtilElectra.java
+++ b/ethereum/spec/src/main/java/tech/pegasys/teku/spec/logic/versions/electra/util/AttestationUtilElectra.java
@@ -262,7 +262,7 @@ private SszBitlist getSingleAttestationAggregationBits(
         .toVersionElectra()
         .orElseThrow()
         .getAttestationSchema()
-        .createAggregationBitsOf(validatorCommitteeBit);
+        .createAggregationBitsOf(committee.size(), validatorCommitteeBit);
   }
 
   private UInt64 getValidatorIndexFromAttestation(