diff --git a/.forge-snapshots/V4Router_Bytecode.snap b/.forge-snapshots/V4Router_Bytecode.snap
index 0f15a960..9c58b982 100644
--- a/.forge-snapshots/V4Router_Bytecode.snap
+++ b/.forge-snapshots/V4Router_Bytecode.snap
@@ -1 +1 @@
-6865
\ No newline at end of file
+7063
\ No newline at end of file
diff --git a/.forge-snapshots/V4Router_ExactOut1Hop_nativeIn_sweepETH.snap b/.forge-snapshots/V4Router_ExactOut1Hop_nativeIn_sweepETH.snap
index 200b076e..0c5ecb08 100644
--- a/.forge-snapshots/V4Router_ExactOut1Hop_nativeIn_sweepETH.snap
+++ b/.forge-snapshots/V4Router_ExactOut1Hop_nativeIn_sweepETH.snap
@@ -1 +1 @@
-121378
\ No newline at end of file
+121413
\ No newline at end of file
diff --git a/.forge-snapshots/V4Router_ExactOut1Hop_nativeOut.snap b/.forge-snapshots/V4Router_ExactOut1Hop_nativeOut.snap
index eaba0d1d..da6da4ca 100644
--- a/.forge-snapshots/V4Router_ExactOut1Hop_nativeOut.snap
+++ b/.forge-snapshots/V4Router_ExactOut1Hop_nativeOut.snap
@@ -1 +1 @@
-116679
\ No newline at end of file
+116714
\ No newline at end of file
diff --git a/.forge-snapshots/V4Router_ExactOut1Hop_oneForZero.snap b/.forge-snapshots/V4Router_ExactOut1Hop_oneForZero.snap
index 82d6a826..f78f106c 100644
--- a/.forge-snapshots/V4Router_ExactOut1Hop_oneForZero.snap
+++ b/.forge-snapshots/V4Router_ExactOut1Hop_oneForZero.snap
@@ -1 +1 @@
-125494
\ No newline at end of file
+125529
\ No newline at end of file
diff --git a/.forge-snapshots/V4Router_ExactOut1Hop_zeroForOne.snap b/.forge-snapshots/V4Router_ExactOut1Hop_zeroForOne.snap
index b62c9b2c..4645416b 100644
--- a/.forge-snapshots/V4Router_ExactOut1Hop_zeroForOne.snap
+++ b/.forge-snapshots/V4Router_ExactOut1Hop_zeroForOne.snap
@@ -1 +1 @@
-129411
\ No newline at end of file
+129446
\ No newline at end of file
diff --git a/.forge-snapshots/V4Router_ExactOut2Hops.snap b/.forge-snapshots/V4Router_ExactOut2Hops.snap
index c5327835..69edacf1 100644
--- a/.forge-snapshots/V4Router_ExactOut2Hops.snap
+++ b/.forge-snapshots/V4Router_ExactOut2Hops.snap
@@ -1 +1 @@
-179239
\ No newline at end of file
+179274
\ No newline at end of file
diff --git a/.forge-snapshots/V4Router_ExactOut2Hops_nativeIn.snap b/.forge-snapshots/V4Router_ExactOut2Hops_nativeIn.snap
index edc46c28..93480400 100644
--- a/.forge-snapshots/V4Router_ExactOut2Hops_nativeIn.snap
+++ b/.forge-snapshots/V4Router_ExactOut2Hops_nativeIn.snap
@@ -1 +1 @@
-175123
\ No newline at end of file
+175158
\ No newline at end of file
diff --git a/.forge-snapshots/V4Router_ExactOut3Hops.snap b/.forge-snapshots/V4Router_ExactOut3Hops.snap
index dd6100a3..920f4b7a 100644
--- a/.forge-snapshots/V4Router_ExactOut3Hops.snap
+++ b/.forge-snapshots/V4Router_ExactOut3Hops.snap
@@ -1 +1 @@
-229074
\ No newline at end of file
+229109
\ No newline at end of file
diff --git a/.forge-snapshots/V4Router_ExactOut3Hops_nativeIn.snap b/.forge-snapshots/V4Router_ExactOut3Hops_nativeIn.snap
index ecf0f6d4..cb98d71e 100644
--- a/.forge-snapshots/V4Router_ExactOut3Hops_nativeIn.snap
+++ b/.forge-snapshots/V4Router_ExactOut3Hops_nativeIn.snap
@@ -1 +1 @@
-224982
\ No newline at end of file
+225017
\ No newline at end of file
diff --git a/.forge-snapshots/V4Router_ExactOut3Hops_nativeOut.snap b/.forge-snapshots/V4Router_ExactOut3Hops_nativeOut.snap
index d3a34986..403f0404 100644
--- a/.forge-snapshots/V4Router_ExactOut3Hops_nativeOut.snap
+++ b/.forge-snapshots/V4Router_ExactOut3Hops_nativeOut.snap
@@ -1 +1 @@
-220283
\ No newline at end of file
+220318
\ No newline at end of file
diff --git a/.forge-snapshots/V4Router_ExactOutputSingle.snap b/.forge-snapshots/V4Router_ExactOutputSingle.snap
index 9fde061b..1c160394 100644
--- a/.forge-snapshots/V4Router_ExactOutputSingle.snap
+++ b/.forge-snapshots/V4Router_ExactOutputSingle.snap
@@ -1 +1 @@
-128684
\ No newline at end of file
+128716
\ No newline at end of file
diff --git a/.forge-snapshots/V4Router_ExactOutputSingle_nativeIn_sweepETH.snap b/.forge-snapshots/V4Router_ExactOutputSingle_nativeIn_sweepETH.snap
index 68c0e2f2..1601b618 100644
--- a/.forge-snapshots/V4Router_ExactOutputSingle_nativeIn_sweepETH.snap
+++ b/.forge-snapshots/V4Router_ExactOutputSingle_nativeIn_sweepETH.snap
@@ -1 +1 @@
-120651
\ No newline at end of file
+120683
\ No newline at end of file
diff --git a/.forge-snapshots/V4Router_ExactOutputSingle_nativeOut.snap b/.forge-snapshots/V4Router_ExactOutputSingle_nativeOut.snap
index 587b0484..ff5267a5 100644
--- a/.forge-snapshots/V4Router_ExactOutputSingle_nativeOut.snap
+++ b/.forge-snapshots/V4Router_ExactOutputSingle_nativeOut.snap
@@ -1 +1 @@
-116027
\ No newline at end of file
+116059
\ No newline at end of file
diff --git a/src/V4Router.sol b/src/V4Router.sol
index fb806eb4..b33d8d90 100644
--- a/src/V4Router.sol
+++ b/src/V4Router.sol
@@ -121,13 +121,18 @@ abstract contract V4Router is IV4Router, BaseActionsRouter, DeltaResolver {
     }
 
     function _swapExactOutputSingle(IV4Router.ExactOutputSingleParams calldata params) private {
+        uint128 amountOut = params.amountOut;
+        if (amountOut == ActionConstants.OPEN_DELTA) {
+            amountOut =
+                _getFullDebt(params.zeroForOne ? params.poolKey.currency1 : params.poolKey.currency0).toUint128();
+        }
         uint128 amountIn = (
             uint256(
                 -int256(
                     _swap(
                         params.poolKey,
                         params.zeroForOne,
-                        int256(uint256(params.amountOut)),
+                        int256(uint256(amountOut)),
                         params.sqrtPriceLimitX96,
                         params.hookData
                     )
@@ -146,6 +151,10 @@ abstract contract V4Router is IV4Router, BaseActionsRouter, DeltaResolver {
             Currency currencyOut = params.currencyOut;
             PathKey calldata pathKey;
 
+            if (amountOut == ActionConstants.OPEN_DELTA) {
+                amountOut = _getFullDebt(currencyOut).toUint128();
+            }
+
             for (uint256 i = pathLength; i > 0; i--) {
                 pathKey = params.path[i - 1];
                 (PoolKey memory poolKey, bool oneForZero) = pathKey.getPoolAndSwapDirection(currencyOut);
diff --git a/test/router/V4Router.t.sol b/test/router/V4Router.t.sol
index ea2696bc..e32da052 100644
--- a/test/router/V4Router.t.sol
+++ b/test/router/V4Router.t.sol
@@ -534,6 +534,35 @@ contract V4RouterTest is RoutingTestHelpers {
         assertEq(outputBalanceAfter - outputBalanceBefore, amountOut);
     }
 
+    function test_swapExactOutputSingle_swapOpenDelta() public {
+        uint256 expectedAmountIn = 1008049273448486163;
+
+        IV4Router.ExactOutputSingleParams memory params = IV4Router.ExactOutputSingleParams(
+            key0, true, ActionConstants.OPEN_DELTA, uint128(expectedAmountIn + 1), 0, bytes("")
+        );
+
+        plan = plan.add(Actions.TAKE, abi.encode(key0.currency1, ActionConstants.ADDRESS_THIS, 1 ether));
+        plan = plan.add(Actions.SWAP_EXACT_OUT_SINGLE, abi.encode(params));
+        plan = plan.add(Actions.SETTLE, abi.encode(key0.currency0, ActionConstants.OPEN_DELTA, true));
+
+        bytes memory data = plan.encode();
+
+        uint256 callerInputBefore = key0.currency0.balanceOfSelf();
+        uint256 routerInputBefore = key0.currency1.balanceOfSelf();
+        uint256 callerOutputBefore = key0.currency1.balanceOfSelf();
+
+        router.executeActions(data);
+
+        uint256 callerInputAfter = key0.currency0.balanceOfSelf();
+        uint256 routerInputAfter = key0.currency1.balanceOfSelf();
+        uint256 callerOutputAfter = key0.currency1.balanceOfSelf();
+
+        // caller paid
+        assertEq(callerInputBefore - expectedAmountIn, callerInputAfter);
+        assertEq(routerInputBefore, routerInputAfter);
+        assertEq(callerOutputBefore, callerOutputAfter);
+    }
+
     function test_swapExactOut_revertsForAmountIn() public {
         uint256 amountOut = 1 ether;
         uint256 expectedAmountIn = 1008049273448486163;
@@ -641,6 +670,36 @@ contract V4RouterTest is RoutingTestHelpers {
         assertEq(outputBalanceAfter - outputBalanceBefore, amountOut);
     }
 
+    function test_swapExactOut_swapOpenDelta() public {
+        uint256 expectedAmountIn = 1008049273448486163;
+
+        tokenPath.push(currency0);
+        tokenPath.push(currency1);
+
+        IV4Router.ExactOutputParams memory params = _getExactOutputParams(tokenPath, ActionConstants.OPEN_DELTA);
+
+        plan = plan.add(Actions.TAKE, abi.encode(key0.currency1, ActionConstants.ADDRESS_THIS, 1 ether));
+        plan = plan.add(Actions.SWAP_EXACT_OUT, abi.encode(params));
+        plan = plan.add(Actions.SETTLE, abi.encode(key0.currency0, ActionConstants.OPEN_DELTA, true));
+
+        bytes memory data = plan.encode();
+
+        uint256 callerInputBefore = key0.currency0.balanceOfSelf();
+        uint256 routerInputBefore = key0.currency1.balanceOfSelf();
+        uint256 callerOutputBefore = key0.currency1.balanceOfSelf();
+
+        router.executeActions(data);
+
+        uint256 callerInputAfter = key0.currency0.balanceOfSelf();
+        uint256 routerInputAfter = key0.currency1.balanceOfSelf();
+        uint256 callerOutputAfter = key0.currency1.balanceOfSelf();
+
+        // caller paid
+        assertEq(callerInputBefore - expectedAmountIn, callerInputAfter);
+        assertEq(routerInputBefore, routerInputAfter);
+        assertEq(callerOutputBefore, callerOutputAfter);
+    }
+
     /*//////////////////////////////////////////////////////////////
                 ETH -> ERC20 and ERC20 -> ETH EXACT OUTPUT
     //////////////////////////////////////////////////////////////*/