diff --git a/.forge-snapshots/Base-V2DutchOrder-BaseExecuteSingleWithFee.snap b/.forge-snapshots/Base-V2DutchOrder-BaseExecuteSingleWithFee.snap
index 601dff7d..a583ac2c 100644
--- a/.forge-snapshots/Base-V2DutchOrder-BaseExecuteSingleWithFee.snap
+++ b/.forge-snapshots/Base-V2DutchOrder-BaseExecuteSingleWithFee.snap
@@ -1 +1 @@
-188641
\ No newline at end of file
+188652
\ No newline at end of file
diff --git a/.forge-snapshots/Base-V2DutchOrder-ExclusiveFiller.snap b/.forge-snapshots/Base-V2DutchOrder-ExclusiveFiller.snap
index 5677f710..df812dd9 100644
--- a/.forge-snapshots/Base-V2DutchOrder-ExclusiveFiller.snap
+++ b/.forge-snapshots/Base-V2DutchOrder-ExclusiveFiller.snap
@@ -1 +1 @@
-158755
\ No newline at end of file
+158766
\ No newline at end of file
diff --git a/.forge-snapshots/Base-V2DutchOrder-ExecuteBatch.snap b/.forge-snapshots/Base-V2DutchOrder-ExecuteBatch.snap
index 6c6670d1..e8e31f23 100644
--- a/.forge-snapshots/Base-V2DutchOrder-ExecuteBatch.snap
+++ b/.forge-snapshots/Base-V2DutchOrder-ExecuteBatch.snap
@@ -1 +1 @@
-210706
\ No newline at end of file
+210728
\ No newline at end of file
diff --git a/.forge-snapshots/Base-V2DutchOrder-ExecuteBatchMultipleOutputs.snap b/.forge-snapshots/Base-V2DutchOrder-ExecuteBatchMultipleOutputs.snap
index dd014aba..2744d377 100644
--- a/.forge-snapshots/Base-V2DutchOrder-ExecuteBatchMultipleOutputs.snap
+++ b/.forge-snapshots/Base-V2DutchOrder-ExecuteBatchMultipleOutputs.snap
@@ -1 +1 @@
-220975
\ No newline at end of file
+220997
\ No newline at end of file
diff --git a/.forge-snapshots/Base-V2DutchOrder-ExecuteBatchMultipleOutputsDifferentTokens.snap b/.forge-snapshots/Base-V2DutchOrder-ExecuteBatchMultipleOutputsDifferentTokens.snap
index 3e76aa79..c0830615 100644
--- a/.forge-snapshots/Base-V2DutchOrder-ExecuteBatchMultipleOutputsDifferentTokens.snap
+++ b/.forge-snapshots/Base-V2DutchOrder-ExecuteBatchMultipleOutputsDifferentTokens.snap
@@ -1 +1 @@
-275146
\ No newline at end of file
+275168
\ No newline at end of file
diff --git a/.forge-snapshots/Base-V2DutchOrder-ExecuteBatchNativeOutput.snap b/.forge-snapshots/Base-V2DutchOrder-ExecuteBatchNativeOutput.snap
index f3b5e6a6..6d59fdab 100644
--- a/.forge-snapshots/Base-V2DutchOrder-ExecuteBatchNativeOutput.snap
+++ b/.forge-snapshots/Base-V2DutchOrder-ExecuteBatchNativeOutput.snap
@@ -1 +1 @@
-204232
\ No newline at end of file
+204254
\ No newline at end of file
diff --git a/.forge-snapshots/Base-V2DutchOrder-ExecuteSingle.snap b/.forge-snapshots/Base-V2DutchOrder-ExecuteSingle.snap
index 5d46966b..11cee36c 100644
--- a/.forge-snapshots/Base-V2DutchOrder-ExecuteSingle.snap
+++ b/.forge-snapshots/Base-V2DutchOrder-ExecuteSingle.snap
@@ -1 +1 @@
-155058
\ No newline at end of file
+155069
\ No newline at end of file
diff --git a/.forge-snapshots/Base-V2DutchOrder-ExecuteSingleNativeOutput.snap b/.forge-snapshots/Base-V2DutchOrder-ExecuteSingleNativeOutput.snap
index 0e39af06..7b7b7e20 100644
--- a/.forge-snapshots/Base-V2DutchOrder-ExecuteSingleNativeOutput.snap
+++ b/.forge-snapshots/Base-V2DutchOrder-ExecuteSingleNativeOutput.snap
@@ -1 +1 @@
-140620
\ No newline at end of file
+140631
\ No newline at end of file
diff --git a/.forge-snapshots/Base-V2DutchOrder-ExecuteSingleValidation.snap b/.forge-snapshots/Base-V2DutchOrder-ExecuteSingleValidation.snap
index 8e5ca1e0..00609fa9 100644
--- a/.forge-snapshots/Base-V2DutchOrder-ExecuteSingleValidation.snap
+++ b/.forge-snapshots/Base-V2DutchOrder-ExecuteSingleValidation.snap
@@ -1 +1 @@
-164369
\ No newline at end of file
+164380
\ No newline at end of file
diff --git a/.forge-snapshots/Base-V2DutchOrder-InputOverride.snap b/.forge-snapshots/Base-V2DutchOrder-InputOverride.snap
index 5fa28dab..a8aa2096 100644
--- a/.forge-snapshots/Base-V2DutchOrder-InputOverride.snap
+++ b/.forge-snapshots/Base-V2DutchOrder-InputOverride.snap
@@ -1 +1 @@
-159044
\ No newline at end of file
+159055
\ No newline at end of file
diff --git a/.forge-snapshots/Base-V2DutchOrder-OutputOverride.snap b/.forge-snapshots/Base-V2DutchOrder-OutputOverride.snap
index 46886e0b..bb228056 100644
--- a/.forge-snapshots/Base-V2DutchOrder-OutputOverride.snap
+++ b/.forge-snapshots/Base-V2DutchOrder-OutputOverride.snap
@@ -1 +1 @@
-158782
\ No newline at end of file
+158793
\ No newline at end of file
diff --git a/src/reactors/V2DutchOrderReactor.sol b/src/reactors/V2DutchOrderReactor.sol
index fec9c873..f7ca769d 100644
--- a/src/reactors/V2DutchOrderReactor.sol
+++ b/src/reactors/V2DutchOrderReactor.sol
@@ -124,7 +124,7 @@ contract V2DutchOrderReactor is BaseReactor {
         uint8 v = uint8(order.cosignature[64]);
         // cosigner signs over (orderHash || cosignerData)
         address signer = ecrecover(keccak256(abi.encodePacked(orderHash, abi.encode(order.cosignerData))), v, r, s);
-        if (order.cosigner != signer && signer != address(0)) {
+        if (order.cosigner != signer || signer == address(0)) {
             revert InvalidCosignature();
         }
 
diff --git a/test/reactors/V2DutchOrderReactor.t.sol b/test/reactors/V2DutchOrderReactor.t.sol
index 7c47847b..63f78a1d 100644
--- a/test/reactors/V2DutchOrderReactor.t.sol
+++ b/test/reactors/V2DutchOrderReactor.t.sol
@@ -121,7 +121,7 @@ contract V2DutchOrderTest is PermitSignature, DeployPermit2, BaseDutchOrderReact
         return (SignedOrder(abi.encode(order), signOrder(swapperPrivateKey, address(permit2), order)), orderHash);
     }
 
-    function testInvalidCosignature() public {
+    function testWrongCosigner() public {
         address wrongCosigner = makeAddr("wrongCosigner");
         CosignerData memory cosignerData = CosignerData({
             decayStartTime: block.timestamp,
@@ -147,6 +147,32 @@ contract V2DutchOrderTest is PermitSignature, DeployPermit2, BaseDutchOrderReact
         fillContract.execute(signedOrder);
     }
 
+    function testInvalidCosignature() public {
+        address wrongCosigner = makeAddr("wrongCosigner");
+        CosignerData memory cosignerData = CosignerData({
+            decayStartTime: block.timestamp,
+            decayEndTime: block.timestamp + 100,
+            exclusiveFiller: address(0),
+            exclusivityOverrideBps: 0,
+            inputAmount: 1 ether,
+            outputAmounts: ArrayBuilder.fill(1, 1 ether)
+        });
+
+        V2DutchOrder memory order = V2DutchOrder({
+            info: OrderInfoBuilder.init(address(reactor)).withSwapper(swapper),
+            cosigner: wrongCosigner,
+            baseInput: DutchInput(tokenIn, 1 ether, 1 ether),
+            baseOutputs: OutputsBuilder.singleDutch(address(tokenOut), 1 ether, 1 ether, swapper),
+            cosignerData: cosignerData,
+            cosignature: bytes("")
+        });
+        order.cosignature = bytes.concat(keccak256("invalidSignature"), keccak256("invalidSignature"), hex"33");
+        SignedOrder memory signedOrder =
+            SignedOrder(abi.encode(order), signOrder(swapperPrivateKey, address(permit2), order));
+        vm.expectRevert(V2DutchOrderReactor.InvalidCosignature.selector);
+        fillContract.execute(signedOrder);
+    }
+
     function testInputOverrideWorse() public {
         CosignerData memory cosignerData = CosignerData({
             decayStartTime: block.timestamp,