diff --git a/contracts/exchange/contracts/test/ReentrancyTester.sol b/contracts/exchange/contracts/test/ReentrancyTester.sol
index 05c845e160..897dbecd1b 100644
--- a/contracts/exchange/contracts/test/ReentrancyTester.sol
+++ b/contracts/exchange/contracts/test/ReentrancyTester.sol
@@ -65,13 +65,12 @@ contract ReentrancyTester is
     }
 
     /// @dev Overridden to revert on unsuccessful fillOrder call.
-    function fillOrderNoThrow(
+    function _fillOrderNoThrow(
         LibOrder.Order memory order,
         uint256 takerAssetFillAmount,
         bytes memory signature
     )
-        public
-        payable
+        internal
         returns (LibFillResults.FillResults memory fillResults)
     {
         // ABI encode calldata for `fillOrder`
diff --git a/contracts/exchange/test/signature_validator.ts b/contracts/exchange/test/signature_validator.ts
index 9ebd9ae248..7ba9dcde48 100644
--- a/contracts/exchange/test/signature_validator.ts
+++ b/contracts/exchange/test/signature_validator.ts
@@ -575,6 +575,27 @@ blockchainTests.resets('MixinSignatureValidator', env => {
             return expect(tx).to.revertWith(expectedError);
         });
 
+        it('should revert when SignatureType=Validator and signature is shorter than 21 bytes', async () => {
+            // Set approval of signature validator to false
+            await signatureValidator.setSignatureValidatorApproval.awaitTransactionSuccessAsync(
+                validatorWallet.address,
+                false,
+                { from: signedOrder.makerAddress },
+            );
+            // Doesn't have to contain a real signature since our wallet contract
+            // just does a hash comparison.
+            const signatureHex = hexConcat(SignatureType.Validator);
+            const orderHashHex = orderHashUtils.getOrderHashHex(signedOrder);
+            const expectedError = new ExchangeRevertErrors.SignatureError(
+                ExchangeRevertErrors.SignatureErrorCode.InvalidLength,
+                orderHashHex,
+                signedOrder.makerAddress,
+                signatureHex,
+            );
+            const tx = validateAsync(signedOrder, signatureHex, ValidatorWalletAction.MatchSignatureHash);
+            return expect(tx).to.revertWith(expectedError);
+        });
+
         it('should revert when SignatureType=Validator, signature is valid and validator is not approved', async () => {
             // Set approval of signature validator to false
             await signatureValidator.setSignatureValidatorApproval.awaitTransactionSuccessAsync(
@@ -837,6 +858,27 @@ blockchainTests.resets('MixinSignatureValidator', env => {
             expect(isValidSignature).to.be.false();
         });
 
+        it('should revert when SignatureType=Validator and signature is shorter than 21 bytes', async () => {
+            // Set approval of signature validator to false
+            await signatureValidator.setSignatureValidatorApproval.awaitTransactionSuccessAsync(
+                validatorWallet.address,
+                false,
+                { from: signedTransaction.signerAddress },
+            );
+            // Doesn't have to contain a real signature since our wallet contract
+            // just does a hash comparison.
+            const signatureHex = hexConcat(SignatureType.Validator);
+            const transactionHashHex = transactionHashUtils.getTransactionHashHex(signedTransaction);
+            const expectedError = new ExchangeRevertErrors.SignatureError(
+                ExchangeRevertErrors.SignatureErrorCode.InvalidLength,
+                transactionHashHex,
+                signedTransaction.signerAddress,
+                signatureHex,
+            );
+            const tx = validateAsync(signedTransaction, signatureHex, ValidatorWalletAction.MatchSignatureHash);
+            return expect(tx).to.revertWith(expectedError);
+        });
+
         it('should revert when validator returns nothing and SignatureType=Validator', async () => {
             const signatureDataHex = generateRandomSignature();
             const signatureHex = hexConcat(signatureDataHex, validatorWallet.address, SignatureType.Validator);
diff --git a/contracts/utils/test/lib_bytes.ts b/contracts/utils/test/lib_bytes.ts
index 0d79c05852..ace87b530e 100644
--- a/contracts/utils/test/lib_bytes.ts
+++ b/contracts/utils/test/lib_bytes.ts
@@ -668,7 +668,7 @@ describe('LibBytes', () => {
     describe('writeBytesWithLength', () => {
         it('should successfully write short, nested array of bytes when it takes up the whole array', async () => {
             const testBytesOffset = new BigNumber(0);
-            const emptyByteArray = ethUtil.bufferToHex(ethUtil.toBuffer(shortTestBytesAsBuffer.byteLength));
+            const emptyByteArray = ethUtil.bufferToHex(Buffer.alloc(shortTestBytesAsBuffer.byteLength));
             const bytesWritten = await libBytes.publicWriteBytesWithLength.callAsync(
                 emptyByteArray,
                 testBytesOffset,
@@ -683,7 +683,7 @@ describe('LibBytes', () => {
             const prefixDataAsBuffer = ethUtil.toBuffer(prefixData);
             const prefixOffset = new BigNumber(0);
             const emptyByteArray = ethUtil.bufferToHex(
-                ethUtil.toBuffer(prefixDataAsBuffer.byteLength + shortTestBytesAsBuffer.byteLength),
+                Buffer.alloc(prefixDataAsBuffer.byteLength + shortTestBytesAsBuffer.byteLength),
             );
             let bytesWritten = await libBytes.publicWriteBytesWithLength.callAsync(
                 emptyByteArray,
@@ -703,7 +703,7 @@ describe('LibBytes', () => {
         });
         it('should successfully write a nested array of bytes - one word in length - when it takes up the whole array', async () => {
             const testBytesOffset = new BigNumber(0);
-            const emptyByteArray = ethUtil.bufferToHex(ethUtil.toBuffer(wordOfTestBytesAsBuffer.byteLength));
+            const emptyByteArray = ethUtil.bufferToHex(Buffer.alloc(wordOfTestBytesAsBuffer.byteLength));
             const bytesWritten = await libBytes.publicWriteBytesWithLength.callAsync(
                 emptyByteArray,
                 testBytesOffset,
@@ -718,7 +718,7 @@ describe('LibBytes', () => {
             const prefixDataAsBuffer = ethUtil.toBuffer(prefixData);
             const prefixOffset = new BigNumber(0);
             const emptyByteArray = ethUtil.bufferToHex(
-                ethUtil.toBuffer(prefixDataAsBuffer.byteLength + wordOfTestBytesAsBuffer.byteLength),
+                Buffer.alloc(prefixDataAsBuffer.byteLength + wordOfTestBytesAsBuffer.byteLength),
             );
             let bytesWritten = await libBytes.publicWriteBytesWithLength.callAsync(
                 emptyByteArray,
@@ -738,7 +738,7 @@ describe('LibBytes', () => {
         });
         it('should successfully write a long, nested bytes when it takes up the whole array', async () => {
             const testBytesOffset = new BigNumber(0);
-            const emptyByteArray = ethUtil.bufferToHex(ethUtil.toBuffer(longTestBytesAsBuffer.byteLength));
+            const emptyByteArray = ethUtil.bufferToHex(Buffer.alloc(longTestBytesAsBuffer.byteLength));
             const bytesWritten = await libBytes.publicWriteBytesWithLength.callAsync(
                 emptyByteArray,
                 testBytesOffset,
@@ -753,7 +753,7 @@ describe('LibBytes', () => {
             const prefixDataAsBuffer = ethUtil.toBuffer(prefixData);
             const prefixOffset = new BigNumber(0);
             const emptyByteArray = ethUtil.bufferToHex(
-                ethUtil.toBuffer(prefixDataAsBuffer.byteLength + longTestBytesAsBuffer.byteLength),
+                Buffer.alloc(prefixDataAsBuffer.byteLength + longTestBytesAsBuffer.byteLength),
             );
             let bytesWritten = await libBytes.publicWriteBytesWithLength.callAsync(
                 emptyByteArray,
@@ -769,7 +769,7 @@ describe('LibBytes', () => {
         });
         it('should fail if the byte array is too short to hold the length of a nested byte array', async () => {
             const offset = new BigNumber(0);
-            const emptyByteArray = ethUtil.bufferToHex(ethUtil.toBuffer(1));
+            const emptyByteArray = ethUtil.bufferToHex(Buffer.alloc(1));
             const inputLen = new BigNumber((longData.length - 2) / 2);
             const expectedError = new LibBytesRevertErrors.InvalidByteOperationError(
                 LibBytesRevertErrors.InvalidByteOperationErrorCodes.LengthGreaterThanOrEqualsNestedBytesLengthRequired,
@@ -781,7 +781,7 @@ describe('LibBytes', () => {
             ).to.revertWith(expectedError);
         });
         it('should fail if the length between the offset and end of the byte array is too short to hold the length of a nested byte array', async () => {
-            const emptyByteArray = ethUtil.bufferToHex(ethUtil.toBuffer(shortTestBytesAsBuffer.byteLength));
+            const emptyByteArray = ethUtil.bufferToHex(Buffer.alloc(shortTestBytesAsBuffer.byteLength));
             const badOffset = new BigNumber(ethUtil.toBuffer(shortTestBytesAsBuffer).byteLength);
             const inputLen = new BigNumber((shortData.length - 2) / 2);
             const expectedError = new LibBytesRevertErrors.InvalidByteOperationError(