diff --git a/contracts/NonfungiblePositionManagerV4.sol b/contracts/NonfungiblePositionManagerV4.sol
index 53c4ff31..cd10dd87 100644
--- a/contracts/NonfungiblePositionManagerV4.sol
+++ b/contracts/NonfungiblePositionManagerV4.sol
@@ -15,11 +15,6 @@ import {PeripheryPayments} from "./base/PeripheryPayments.sol";
 import {SelfPermit} from "./base/SelfPermit.sol";
 import {Multicall} from "./base/Multicall.sol";
 
-error InvalidTokenID();
-error NotApproved();
-error NotCleared();
-error NonexistentToken();
-
 contract NonfungiblePositionManagerV4 is
     INonfungiblePositionManagerV4,
     ERC721,
@@ -30,6 +25,11 @@ contract NonfungiblePositionManagerV4 is
 {
     IPoolManager public immutable poolManager;
 
+    error InvalidTokenID();
+    error NotApproved();
+    error NotCleared();
+    error NonexistentToken();
+
     // details about the Uniswap position
     struct Position {
         // the nonce for permits
@@ -111,6 +111,10 @@ contract NonfungiblePositionManagerV4 is
         );
     }
 
+    function lockAcquired(bytes calldata rawData) external returns (bytes memory) {
+        // TODO: implement this
+    }
+
     /// @inheritdoc INonfungiblePositionManagerV4
     function createAndInitializePoolIfNecessary(PoolKey memory poolkey, uint160 sqrtPriceX96, bytes memory initData)
         external
diff --git a/contracts/interfaces/INonfungiblePositionManagerV4.sol b/contracts/interfaces/INonfungiblePositionManagerV4.sol
index d263fc51..624e84b1 100644
--- a/contracts/interfaces/INonfungiblePositionManagerV4.sol
+++ b/contracts/interfaces/INonfungiblePositionManagerV4.sol
@@ -3,6 +3,7 @@ pragma solidity ^0.8.19;
 
 import {IERC721Metadata} from "@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol";
 import {IERC721Enumerable} from "@openzeppelin/contracts/token/ERC721/extensions/IERC721Enumerable.sol";
+import {ILockCallback} from "@uniswap/v4-core/contracts/interfaces/callback//ILockCallback.sol";
 import {PoolKey} from "@uniswap/v4-core/contracts/types/PoolKey.sol";
 import {Currency} from "@uniswap/v4-core/contracts/types/Currency.sol";
 
@@ -11,7 +12,7 @@ import {IPeripheryPayments} from "./IPeripheryPayments.sol";
 /// @title Non-fungible token for positions
 /// @notice Wraps Uniswap V4 positions in a non-fungible token interface which allows for them to be transferred
 /// and authorized.
-interface INonfungiblePositionManagerV4 is IPeripheryPayments, IERC721Metadata, IERC721Enumerable {
+interface INonfungiblePositionManagerV4 is ILockCallback, IPeripheryPayments, IERC721Metadata, IERC721Enumerable {
     /// @notice Emitted when liquidity is increased for a position NFT
     /// @dev Also emitted when a token is minted
     /// @param tokenId The ID of the token for which liquidity was increased