diff --git a/specs/deneb/beacon-chain.md b/specs/deneb/beacon-chain.md
index 1926cc8ce..b2f6b1763 100644
--- a/specs/deneb/beacon-chain.md
+++ b/specs/deneb/beacon-chain.md
@@ -254,6 +254,7 @@ def process_execution_payload(state: BeaconState, payload: ExecutionPayload, exe
 
 ```python
 def process_blob_kzg_commitments(body: BeaconBlockBody) -> None:
+    assert len(body.blob_kzg_commitments) <= MAX_BLOBS_PER_BLOCK
     assert verify_kzg_commitments_against_transactions(body.execution_payload.transactions, body.blob_kzg_commitments)
 ```