diff --git a/test/concrete/OrderBook.takeOrder.handleIO.revert.t.sol b/test/concrete/OrderBook.takeOrder.handleIO.revert.t.sol
new file mode 100644
index 000000000..0c06ca3f6
--- /dev/null
+++ b/test/concrete/OrderBook.takeOrder.handleIO.revert.t.sol
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: CAL
+pragma solidity =0.8.19;
+
+import {Vm} from "forge-std/Vm.sol";
+import {OrderBookExternalRealTest, OrderConfigV2, IO, IParserV1, EvaluableConfigV2, Order, TakeOrderConfig, SignedContextV1, TakeOrdersConfigV2} from "test/util/abstract/OrderBookExternalRealTest.sol";
+import {EnsureFailed} from "rain.interpreter/src/lib/op/logic/LibOpEnsureNP.sol";
+
+/// @title OrderBookTakeOrderHandleIORevertTest
+/// @notice A test harness for testing the OrderBook takeOrder function will run
+/// handle IO and revert if it fails.
+contract OrderBookTakeOrderHandleIORevertTest is OrderBookExternalRealTest {
+    function testTakeOrderHandleIORevert() public {
+        uint256 vaultId = 0;
+        address inputToken = address(0x100);
+        address outputToken = address(0x101);
+        OrderConfigV2 memory config;
+        {
+            IO[] memory validInputs = new IO[](1);
+            validInputs[0] = IO(inputToken, 18, vaultId);
+            IO[] memory validOutputs = new IO[](1);
+            validOutputs[0] = IO(outputToken, 18, vaultId);
+            (bytes memory bytecode, uint256[] memory constants) = IParserV1(address(iDeployer)).parse("_ _:max-int-value() 1e18;:ensure<1>(0);");
+            EvaluableConfigV2 memory evaluableConfig = EvaluableConfigV2(iDeployer, bytecode, constants);
+            config = OrderConfigV2(validInputs, validOutputs, evaluableConfig, "");
+            // Etch with invalid.
+            vm.etch(outputToken, hex"fe");
+            vm.etch(inputToken, hex"fe");
+            // Mock every call to output as a success, so the orderbook thinks it
+            // is transferring tokens.
+            vm.mockCall(outputToken, "", abi.encode(true));
+            vm.mockCall(inputToken, "", abi.encode(true));
+        }
+        iOrderbook.deposit(outputToken, vaultId, type(uint256).max);
+        assertEq(iOrderbook.vaultBalance(address(this), outputToken, vaultId), type(uint256).max);
+
+        vm.recordLogs();
+        iOrderbook.addOrder(config);
+        Vm.Log[] memory entries = vm.getRecordedLogs();
+        assertEq(entries.length, 3);
+        (,, Order memory order,) = abi.decode(entries[2].data, (address, address, Order, bytes32));
+
+        TakeOrderConfig[] memory orders = new TakeOrderConfig[](1);
+        orders[0] = TakeOrderConfig(order, 0, 0, new SignedContextV1[](0));
+        TakeOrdersConfigV2 memory takeOrdersConfig =
+            TakeOrdersConfigV2(0, type(uint256).max, type(uint256).max, orders, "");
+
+        vm.expectRevert(abi.encodeWithSelector(EnsureFailed.selector, 1, 0));
+        (uint256 totalTakerInput, uint256 totalTakerOutput) = iOrderbook.takeOrders(takeOrdersConfig);
+        (totalTakerInput, totalTakerOutput);
+    }
+}
diff --git a/test/concrete/OrderBook.takeOrder.precision.t.sol b/test/concrete/OrderBook.takeOrder.precision.t.sol
index 3ab3606eb..4dcaddcc0 100644
--- a/test/concrete/OrderBook.takeOrder.precision.t.sol
+++ b/test/concrete/OrderBook.takeOrder.precision.t.sol
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: CAL
 pragma solidity =0.8.19;
 
-import "test/util/abstract/OrderBookExternalRealTest.sol";
+import {OrderBookExternalRealTest, OrderConfigV2, IO, EvaluableConfigV2, IParserV1, Vm, Order, TakeOrderConfig, SignedContextV1, TakeOrdersConfigV2} from "test/util/abstract/OrderBookExternalRealTest.sol";
 
 /// @title OrderBookTakeOrderPrecisionTest
 /// @notice A test harness for testing the OrderBook takeOrder function.
diff --git a/test/concrete/OrderBookV3FlashLender.griefRecipient.t.sol b/test/concrete/OrderBookV3FlashLender.griefRecipient.t.sol
index 0265c51af..32a637b7f 100644
--- a/test/concrete/OrderBookV3FlashLender.griefRecipient.t.sol
+++ b/test/concrete/OrderBookV3FlashLender.griefRecipient.t.sol
@@ -49,9 +49,4 @@ contract OrderBookClearTest is OrderBookExternalMockTest {
         vm.expectRevert();
         iOrderbook.flashLoan(IERC3156FlashBorrower(receiver), address(iToken0), amount, data);
     }
-
-    /// Tests that if the receiver is some contract that returns
-    /// `ON_FLASH_LOAN_CALLBACK_SUCCESS`, and the token movements do not error,
-    /// then the flash loan will succeed.
-
 }