diff --git a/src/UniswapFlashLoan.sol b/src/UniswapFlashLoan.sol
index e8324e0..0897fa1 100644
--- a/src/UniswapFlashLoan.sol
+++ b/src/UniswapFlashLoan.sol
@@ -70,6 +70,8 @@ contract UniswapFlashLoan is IUniswapV3FlashCallback, QuarkScript {
      * @param data FlashLoanCallbackPayload encoded to bytes passed from IUniswapV3Pool.flash(); contains scripts info to execute before repaying the flash loan
      */
     function uniswapV3FlashCallback(uint256 fee0, uint256 fee1, bytes calldata data) external {
+        disallowCallback();
+
         FlashLoanCallbackPayload memory input = abi.decode(data, (FlashLoanCallbackPayload));
         IUniswapV3Pool pool =
             IUniswapV3Pool(PoolAddress.computeAddress(UniswapFactoryAddress.getAddress(), input.poolKey));
diff --git a/src/UniswapFlashSwapExactOut.sol b/src/UniswapFlashSwapExactOut.sol
index 2e8f500..b42df87 100644
--- a/src/UniswapFlashSwapExactOut.sol
+++ b/src/UniswapFlashSwapExactOut.sol
@@ -74,6 +74,8 @@ contract UniswapFlashSwapExactOut is IUniswapV3SwapCallback, QuarkScript {
      * @param data FlashSwap encoded to bytes passed from UniswapV3Pool.swap(); contains script info to execute (possibly with checks) before returning the owed amount
      */
     function uniswapV3SwapCallback(int256 amount0Delta, int256 amount1Delta, bytes calldata data) external {
+        disallowCallback();
+
         FlashSwapExactOutInput memory input = abi.decode(data, (FlashSwapExactOutInput));
         IUniswapV3Pool pool =
             IUniswapV3Pool(PoolAddress.computeAddress(UniswapFactoryAddress.getAddress(), input.poolKey));
diff --git a/test/UniswapFlashLoan.t.sol b/test/UniswapFlashLoan.t.sol
index 9c35a4b..072eac7 100644
--- a/test/UniswapFlashLoan.t.sol
+++ b/test/UniswapFlashLoan.t.sol
@@ -187,6 +187,49 @@ contract UniswapFlashLoanTest is Test {
         assertEq(IComet(comet).borrowBalanceOf(address(wallet)), 1000e6);
     }
 
+    function testRevertsForSecondCallback() public {
+        vm.pauseGasMetering();
+        QuarkWallet wallet = QuarkWallet(factory.create(alice, address(0)));
+        address[] memory callContracts = new address[](1);
+        bytes[] memory callDatas = new bytes[](1);
+        // Call into the wallet and try to execute the fallback function again using the callback mechanism
+        callContracts[0] = address(wallet);
+        callDatas[0] = abi.encodeWithSelector(
+            Ethcall.run.selector,
+            address(wallet),
+            abi.encodeCall(UniswapFlashLoan.uniswapV3FlashCallback, (100, 500, bytes(""))),
+            0
+        );
+        QuarkWallet.QuarkOperation memory op = new QuarkOperationHelper().newBasicOpWithCalldata(
+            wallet,
+            uniswapFlashLoan,
+            abi.encodeWithSelector(
+                UniswapFlashLoan.run.selector,
+                UniswapFlashLoan.UniswapFlashLoanPayload({
+                    token0: USDC,
+                    token1: DAI,
+                    fee: 100,
+                    amount0: 1000e6,
+                    amount1: 0,
+                    callContract: multicallAddress,
+                    callData: abi.encodeWithSelector(Multicall.run.selector, callContracts, callDatas)
+                })
+            ),
+            ScriptType.ScriptAddress
+        );
+        bytes memory signature = new SignatureHelper().signOp(alicePrivateKey, wallet, op);
+        vm.resumeGasMetering();
+        vm.expectRevert(
+            abi.encodeWithSelector(
+                Multicall.MulticallError.selector,
+                0,
+                callContracts[0],
+                abi.encodeWithSelector(QuarkWallet.NoActiveCallback.selector)
+            )
+        );
+        wallet.executeQuarkOperation(op, signature);
+    }
+
     function testRevertsForInvalidCaller() public {
         vm.pauseGasMetering();
         QuarkWallet wallet = QuarkWallet(factory.create(alice, address(0)));
diff --git a/test/UniswapFlashSwapExactOut.t.sol b/test/UniswapFlashSwapExactOut.t.sol
index 4db67c9..919ee28 100644
--- a/test/UniswapFlashSwapExactOut.t.sol
+++ b/test/UniswapFlashSwapExactOut.t.sol
@@ -118,6 +118,51 @@ contract UniswapFlashSwapExactOutTest is Test {
         assertEq(IComet(comet).borrowBalanceOf(address(wallet)), borrowAmountOfUSDC);
     }
 
+    function testRevertsForSecondCallback() public {
+        vm.pauseGasMetering();
+        QuarkWallet wallet = QuarkWallet(factory.create(alice, address(0)));
+        // Set up some funds for test
+        deal(WETH, address(wallet), 10 ether);
+        address[] memory callContracts = new address[](1);
+        bytes[] memory callDatas = new bytes[](1);
+        // Call into the wallet and try to execute the fallback function again using the callback mechanism
+        callContracts[0] = address(wallet);
+        callDatas[0] = abi.encodeWithSelector(
+            Ethcall.run.selector,
+            address(wallet),
+            abi.encodeCall(UniswapFlashSwapExactOut.uniswapV3SwapCallback, (100, 500, bytes(""))),
+            0
+        );
+        QuarkWallet.QuarkOperation memory op = new QuarkOperationHelper().newBasicOpWithCalldata(
+            wallet,
+            uniswapFlashSwapExactOut,
+            abi.encodeWithSelector(
+                UniswapFlashSwapExactOut.run.selector,
+                UniswapFlashSwapExactOut.UniswapFlashSwapExactOutPayload({
+                    tokenOut: WETH,
+                    tokenIn: USDC,
+                    fee: 500,
+                    amountOut: 1 ether,
+                    sqrtPriceLimitX96: 0,
+                    callContract: multicallAddress,
+                    callData: abi.encodeWithSelector(Multicall.run.selector, callContracts, callDatas)
+                })
+            ),
+            ScriptType.ScriptAddress
+        );
+        bytes memory signature = new SignatureHelper().signOp(alicePrivateKey, wallet, op);
+        vm.resumeGasMetering();
+        vm.expectRevert(
+            abi.encodeWithSelector(
+                Multicall.MulticallError.selector,
+                0,
+                callContracts[0],
+                abi.encodeWithSelector(QuarkWallet.NoActiveCallback.selector)
+            )
+        );
+        wallet.executeQuarkOperation(op, signature);
+    }
+
     function testInvalidCallerFlashSwap() public {
         vm.pauseGasMetering();
         QuarkWallet wallet = QuarkWallet(factory.create(alice, address(0)));