diff --git a/src/interfaces/bridge/IBridgeReward.sol b/src/interfaces/bridge/IBridgeReward.sol
index 7287064a..4c47527c 100644
--- a/src/interfaces/bridge/IBridgeReward.sol
+++ b/src/interfaces/bridge/IBridgeReward.sol
@@ -5,6 +5,11 @@ pragma solidity ^0.8.9;
 import { IBridgeRewardEvents } from "./events/IBridgeRewardEvents.sol";
 
 interface IBridgeReward is IBridgeRewardEvents {
+  /**
+   * @dev Configuration of gas stipend to ensure sufficient gas after London Hardfork.
+   */
+  function DEFAULT_ADDITION_GAS() external view returns (uint256);
+  
   /**
    * @dev This function allows bridge operators to manually synchronize the reward for a given period length.
    * @param periodCount The length of the reward period for which synchronization is requested.
diff --git a/src/ronin/gateway/BridgeReward.sol b/src/ronin/gateway/BridgeReward.sol
index 7020b2a0..94f3d147 100644
--- a/src/ronin/gateway/BridgeReward.sol
+++ b/src/ronin/gateway/BridgeReward.sol
@@ -16,7 +16,7 @@ import { TUint256Slot } from "../../types/Types.sol";
 import { ErrSyncTooFarPeriod, ErrInvalidArguments, ErrLengthMismatch, ErrUnauthorizedCall } from "../../utils/CommonErrors.sol";
 
 contract BridgeReward is IBridgeReward, BridgeTrackingHelper, HasContracts, RONTransferHelper, Initializable {
-  /// @dev Configuration of gas stipend to ensure sufficient gas after the London Hardfork
+  /// @inheritdoc IBridgeReward
   uint256 public constant DEFAULT_ADDITION_GAS = 6200;
   /// @dev value is equal to keccak256("@ronin.dpos.gateway.BridgeReward.rewardInfo.slot") - 1
   bytes32 private constant $_REWARD_INFO = 0x518cfd198acbffe95e740cfce1af28a3f7de51f0d784893d3d72c5cc59d7062a;