diff --git a/specs/core/0_beacon-chain.md b/specs/core/0_beacon-chain.md
index fbf81917c..35759f691 100644
--- a/specs/core/0_beacon-chain.md
+++ b/specs/core/0_beacon-chain.md
@@ -608,6 +608,7 @@ MAX_DEPOSIT: constant(uint256) = 32  # ETH
 GWEI_PER_ETH: constant(uint256) = 1000000000  # 10**9
 CHAIN_START_FULL_DEPOSIT_THRESHOLD: constant(uint256) = 16384  # 2**14
 DEPOSIT_CONTRACT_TREE_DEPTH: constant(uint256) = 32
+TWO_TO_POWER_OF_TREE_DEPTH: constant(uint256) = 4294967296  # 2**32
 SECONDS_PER_DAY: constant(uint256) = 86400
 
 Eth1Deposit: event({previous_receipt_root: bytes32, data: bytes[2064], deposit_count: uint256})
@@ -623,7 +624,7 @@ def deposit(deposit_parameters: bytes[2048]):
     assert msg.value >= as_wei_value(MIN_DEPOSIT, "ether")
     assert msg.value <= as_wei_value(MAX_DEPOSIT, "ether")
 
-    index: uint256 = self.deposit_count + 2**DEPOSIT_CONTRACT_TREE_DEPTH
+    index: uint256 = self.deposit_count + TWO_TO_POWER_OF_TREE_DEPTH
     msg_gwei_bytes8: bytes[8] = slice(concat("", convert(msg.value / GWEI_PER_ETH, bytes32)), start=24, len=8)
     timestamp_bytes8: bytes[8] = slice(concat("", convert(block.timestamp, bytes32)), start=24, len=8)
     deposit_data: bytes[2064] = concat(msg_gwei_bytes8, timestamp_bytes8, deposit_parameters)