diff --git a/specs/core/0_beacon-chain.md b/specs/core/0_beacon-chain.md
index 2d168cfc2..9f8bec933 100644
--- a/specs/core/0_beacon-chain.md
+++ b/specs/core/0_beacon-chain.md
@@ -1271,7 +1271,7 @@ def process_deposit(state: BeaconState, deposit: Deposit) -> None:
 
     # Verify the Merkle branch
     merkle_branch_is_valid = verify_merkle_branch(
-        leaf=hash(serialize(deposit.data)),  # 48 + 32 + 8 + 96 = 184 bytes serialisation
+        leaf=hash(serialize(deposit.data)),  # 48 + 32 + 8 + 96 = 184 bytes serialization
         proof=deposit.proof,
         depth=DEPOSIT_CONTRACT_TREE_DEPTH,
         index=deposit.index,