diff --git a/specs/phase0/beacon-chain.md b/specs/phase0/beacon-chain.md
index 3d24ff043..1c88c2a4c 100644
--- a/specs/phase0/beacon-chain.md
+++ b/specs/phase0/beacon-chain.md
@@ -609,7 +609,7 @@ def bytes_to_int(data: bytes) -> uint64:
 - `def Verify(PK: BLSPubkey, message: Bytes, signature: BLSSignature) -> bool`
 - `def Aggregate(signatures: Sequence[BLSSignature]) -> BLSSignature`
 - `def FastAggregateVerify(PKs: Sequence[BLSPubkey], message: Bytes, signature: BLSSignature) -> bool`
-- `def AggregateVerify(PKs: Sequence[BLSPubkey], message: Sequence[Bytes], signature: BLSSignature) -> bool`
+- `def AggregateVerify(PKs: Sequence[BLSPubkey], messages: Sequence[Bytes], signature: BLSSignature) -> bool`
 
 Within these specifications, BLS signatures are treated as a module for notational clarity, thus to verify a signature `bls.Verify(...)` is used.