diff --git a/deposit_contract.sol b/deposit_contract.sol
index ee15ba7b7..d756c2524 100644
--- a/deposit_contract.sol
+++ b/deposit_contract.sol
@@ -87,8 +87,8 @@ contract DepositContract is IDepositContract {
         require(signature.length == SIGNATURE_LENGTH);
 
         // FIXME: these are not the Vyper code, but should verify they are not needed
-        // assert(deposit_amount <= 2^64-1);
-        // assert(deposit_count <= 2^64-1);
+        // assert(deposit_amount <= 2**64-1);
+        // assert(deposit_count <= 2**64-1);
 
         // Emit `DepositEvent` log
         bytes memory amount = to_little_endian_64(uint64(deposit_amount));