diff --git a/.gitmodules b/.gitmodules
index 888d42d..690924b 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,6 @@
 [submodule "lib/forge-std"]
 	path = lib/forge-std
 	url = https://github.com/foundry-rs/forge-std
+[submodule "lib/openzeppelin-contracts"]
+	path = lib/openzeppelin-contracts
+	url = https://github.com/OpenZeppelin/openzeppelin-contracts
diff --git a/lib/openzeppelin-contracts b/lib/openzeppelin-contracts
new file mode 160000
index 0000000..e4f7021
--- /dev/null
+++ b/lib/openzeppelin-contracts
@@ -0,0 +1 @@
+Subproject commit e4f70216d759d8e6a64144a9e1f7bbeed78e7079
diff --git a/src/Pectra.sol b/src/Pectra.sol
index 6fdbf0b..4b33fc6 100644
--- a/src/Pectra.sol
+++ b/src/Pectra.sol
@@ -1,7 +1,9 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.28;
 
-contract Pectra {
+import "@openzeppelin/contracts/utils/introspection/IERC165.sol";
+
+contract Pectra is IERC165 {
     address public constant consolidationTarget = 0x0000BBdDc7CE488642fb579F8B00f3a590007251;
     address public constant exitTarget = 0x00000961Ef480Eb55e80D19ad83579A64c007002;
 
@@ -19,7 +21,12 @@ contract Pectra {
     /// @dev Minimum fee required per validator
     uint256 public constant MIN_FEE = 1 wei;
     /// @dev Maximum withdrawal amount as a uint64 (representing 2048 ether in gwei)
-    uint64 public constant MAX_WITHDRAWAL_AMOUNT = 0x1DCD6500000;
+    uint64 public constant MAX_WITHDRAWAL_AMOUNT = 2048000000000; // 2048 ETH in Gwei
+
+    // Interface IDs
+    bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;
+    bytes4 private constant _INTERFACE_ID_ERC721_RECEIVER = 0x150b7a02;
+    bytes4 private constant _INTERFACE_ID_ERC1155_RECEIVER = 0x4e2312e0;
 
     // Failure reason codes as enum
     enum FailureReason {
@@ -28,7 +35,8 @@ contract Pectra {
         INVALID_AMOUNT_LENGTH,
         INVALID_AMOUNT_VALUE,
         FULL_EXIT_NOT_CONFIRMED,
-        AMOUNT_EXCEEDS_MAXIMUM
+        AMOUNT_EXCEEDS_MAXIMUM,
+        FULL_EXIT_WITH_AMOUNT
     }
 
     event ConsolidationFailed(FailureReason reasonCode, bytes sourcePubkey, bytes targetPubkey);
@@ -45,6 +53,19 @@ contract Pectra {
     receive() external payable {}
     fallback() external payable {}
 
+    /**
+     * @dev Implementation of the {IERC165} interface.
+     *
+     * Returns true if this contract implements the interface defined by
+     * `interfaceId`.
+     *
+     * This function call must use less than 30,000 gas.
+     */
+    function supportsInterface(bytes4 interfaceId) public pure override returns (bool) {
+        return interfaceId == _INTERFACE_ID_ERC165 || interfaceId == _INTERFACE_ID_ERC721_RECEIVER
+            || interfaceId == _INTERFACE_ID_ERC1155_RECEIVER;
+    }
+
     function onERC721Received(address, address, uint256, bytes calldata) external pure returns (bytes4) {
         return this.onERC721Received.selector;
     }
@@ -154,6 +175,11 @@ contract Pectra {
 
             bool isZeroAmount = data[i].amount == 0;
 
+            if (data[i].isFullExit && !isZeroAmount) {
+                emit ExecutionLayerExitFailed(FailureReason.FULL_EXIT_WITH_AMOUNT, data[i].pubkey, data[i].amount);
+                continue;
+            }
+
             if (isZeroAmount && !data[i].isFullExit) {
                 emit ExecutionLayerExitFailed(FailureReason.FULL_EXIT_NOT_CONFIRMED, data[i].pubkey, data[i].amount);
                 continue;
diff --git a/test/Pectra.t.sol b/test/Pectra.t.sol
index 4a2ae97..0fac0c7 100644
--- a/test/Pectra.t.sol
+++ b/test/Pectra.t.sol
@@ -327,9 +327,8 @@ contract PectraTest is Test {
     function testBatchELExit_ExceedsMaximumAmount() public {
         Pectra.ExitData[] memory data = new Pectra.ExitData[](1);
         data[0].pubkey = validPubkey();
-        // Set amount to exceed MAX_WITHDRAWAL_AMOUNT
         data[0].amount = pectra.MAX_WITHDRAWAL_AMOUNT() + 1;
-        data[0].isFullExit = true; // Not needed but included for consistency
+        data[0].isFullExit = false; // Changed to false since full exit can't have amount
 
         vm.expectEmit(true, true, true, true);
         emit Pectra.ExecutionLayerExitFailed(
@@ -345,21 +344,36 @@ contract PectraTest is Test {
         Pectra.ExitData[] memory data = new Pectra.ExitData[](1);
         data[0].pubkey = validPubkey();
         data[0].amount = 1000000000; // 1 ether in gwei
-        data[0].isFullExit = true; // Not needed but included for consistency
+        data[0].isFullExit = false; // Changed to false since full exit can't have amount
+
         vm.expectEmit(true, true, true, true);
         emit Pectra.ExecutionLayerExitFailed(Pectra.FailureReason.OPERATION_FAILED, data[0].pubkey, data[0].amount);
+
         vm.prank(address(pectra));
         pectra.batchELExit{value: 1}(data);
         vm.etch(exitTarget, feeCode);
     }
 
+    function testBatchELExit_FullExitWithAmount() public {
+        Pectra.ExitData[] memory data = new Pectra.ExitData[](1);
+        data[0].pubkey = validPubkey();
+        data[0].amount = 1000000000; // 1 ether in gwei
+        data[0].isFullExit = true; // Setting both amount and isFullExit
+
+        vm.expectEmit(true, true, true, true);
+        emit Pectra.ExecutionLayerExitFailed(Pectra.FailureReason.FULL_EXIT_WITH_AMOUNT, data[0].pubkey, data[0].amount);
+
+        vm.prank(address(pectra));
+        pectra.batchELExit{value: 1}(data);
+    }
+
     function testBatchELExit_SuccessWithValidAmount() public {
         uint256 count = 2;
         Pectra.ExitData[] memory data = new Pectra.ExitData[](count);
         for (uint256 i = 0; i < count; i++) {
             data[i].pubkey = validPubkey();
             data[i].amount = 1000000000; // 1 ether in gwei
-            data[i].isFullExit = true; // Not needed but included for consistency
+            data[i].isFullExit = false; // Changed to false since full exit can't have amount
         }
 
         // Get the fee from the target
@@ -459,7 +473,7 @@ contract PectraTest is Test {
         for (uint256 i = 0; i < count; i++) {
             data[i].pubkey = validPubkey();
             data[i].amount = 1000000000; // 1 ether in gwei
-            data[i].isFullExit = true;
+            data[i].isFullExit = false; // Changed to false since full exit can't have amount
         }
 
         // Get the fee from the target