diff --git a/contracts/staking/CHANGELOG.json b/contracts/staking/CHANGELOG.json
index 51328f4e8c..4cdc721b0d 100644
--- a/contracts/staking/CHANGELOG.json
+++ b/contracts/staking/CHANGELOG.json
@@ -5,6 +5,14 @@
             {
                 "note": "Add more overflow safeguards to `LibFixedMath`",
                 "pr": 2255
+            },
+            {
+                "note": "Refactored finalization state.",
+                "pr": 2276
+            },
+            {
+                "note": "Removed protocol fee != 0 assertion.",
+                "pr": 2278
             }
         ]
     },
diff --git a/contracts/staking/contracts/src/fees/MixinExchangeFees.sol b/contracts/staking/contracts/src/fees/MixinExchangeFees.sol
index 576fbe22db..e4f33bb5f1 100644
--- a/contracts/staking/contracts/src/fees/MixinExchangeFees.sol
+++ b/contracts/staking/contracts/src/fees/MixinExchangeFees.sol
@@ -161,19 +161,11 @@ contract MixinExchangeFees is
         private
         view
     {
-        if (protocolFeePaid == 0) {
-            LibRichErrors.rrevert(
-                LibStakingRichErrors.InvalidProtocolFeePaymentError(
-                    LibStakingRichErrors.ProtocolFeePaymentErrorCodes.ZeroProtocolFeePaid,
-                    protocolFeePaid,
-                    msg.value
-                )
-            );
-        }
+        // The protocol fee must equal the value passed to the contract; unless
+        // the value is zero, in which case the fee is taken in WETH.
         if (msg.value != protocolFeePaid && msg.value != 0) {
             LibRichErrors.rrevert(
                 LibStakingRichErrors.InvalidProtocolFeePaymentError(
-                    LibStakingRichErrors.ProtocolFeePaymentErrorCodes.MismatchedFeeAndPayment,
                     protocolFeePaid,
                     msg.value
                 )
diff --git a/contracts/staking/contracts/src/libs/LibStakingRichErrors.sol b/contracts/staking/contracts/src/libs/LibStakingRichErrors.sol
index 30117d9ce8..6acca6d6b7 100644
--- a/contracts/staking/contracts/src/libs/LibStakingRichErrors.sol
+++ b/contracts/staking/contracts/src/libs/LibStakingRichErrors.sol
@@ -29,11 +29,6 @@ library LibStakingRichErrors {
         CanOnlyDecreaseOperatorShare
     }
 
-    enum ProtocolFeePaymentErrorCodes {
-        ZeroProtocolFeePaid,
-        MismatchedFeeAndPayment
-    }
-
     enum InitializationErrorCodes {
         MixinSchedulerAlreadyInitialized,
         MixinParamsAlreadyInitialized
@@ -104,9 +99,9 @@ library LibStakingRichErrors {
     bytes4 internal constant INVALID_PARAM_VALUE_ERROR_SELECTOR =
         0xfc45bd11;
 
-    // bytes4(keccak256("InvalidProtocolFeePaymentError(uint8,uint256,uint256)"))
+    // bytes4(keccak256("InvalidProtocolFeePaymentError(uint256,uint256)"))
     bytes4 internal constant INVALID_PROTOCOL_FEE_PAYMENT_ERROR_SELECTOR =
-        0xefd6cb33;
+        0x31d7a505;
 
     // bytes4(keccak256("PreviousEpochNotFinalizedError(uint256,uint256)"))
     bytes4 internal constant PREVIOUS_EPOCH_NOT_FINALIZED_ERROR_SELECTOR =
@@ -252,7 +247,6 @@ library LibStakingRichErrors {
     }
 
     function InvalidProtocolFeePaymentError(
-        ProtocolFeePaymentErrorCodes errorCodes,
         uint256 expectedProtocolFeePaid,
         uint256 actualProtocolFeePaid
     )
@@ -262,7 +256,6 @@ library LibStakingRichErrors {
     {
         return abi.encodeWithSelector(
             INVALID_PROTOCOL_FEE_PAYMENT_ERROR_SELECTOR,
-            errorCodes,
             expectedProtocolFeePaid,
             actualProtocolFeePaid
         );
diff --git a/contracts/staking/test/unit_tests/protocol_fees_test.ts b/contracts/staking/test/unit_tests/protocol_fees_test.ts
index d5b5dcd53d..9f3a917910 100644
--- a/contracts/staking/test/unit_tests/protocol_fees_test.ts
+++ b/contracts/staking/test/unit_tests/protocol_fees_test.ts
@@ -90,21 +90,6 @@ blockchainTests('Protocol Fees unit tests', env => {
                 return expect(tx).to.revertWith(expectedError);
             });
 
-            it('should revert if `protocolFeePaid` is zero with zero value sent', async () => {
-                const tx = testContract.payProtocolFee.awaitTransactionSuccessAsync(
-                    makerAddress,
-                    payerAddress,
-                    ZERO_AMOUNT,
-                    { from: exchangeAddress, value: ZERO_AMOUNT },
-                );
-                const expectedError = new StakingRevertErrors.InvalidProtocolFeePaymentError(
-                    StakingRevertErrors.ProtocolFeePaymentErrorCodes.ZeroProtocolFeePaid,
-                    ZERO_AMOUNT,
-                    ZERO_AMOUNT,
-                );
-                return expect(tx).to.revertWith(expectedError);
-            });
-
             it('should revert if `protocolFeePaid` is zero with non-zero value sent', async () => {
                 const tx = testContract.payProtocolFee.awaitTransactionSuccessAsync(
                     makerAddress,
@@ -113,7 +98,6 @@ blockchainTests('Protocol Fees unit tests', env => {
                     { from: exchangeAddress, value: DEFAULT_PROTOCOL_FEE_PAID },
                 );
                 const expectedError = new StakingRevertErrors.InvalidProtocolFeePaymentError(
-                    StakingRevertErrors.ProtocolFeePaymentErrorCodes.ZeroProtocolFeePaid,
                     ZERO_AMOUNT,
                     DEFAULT_PROTOCOL_FEE_PAID,
                 );
@@ -128,7 +112,6 @@ blockchainTests('Protocol Fees unit tests', env => {
                     { from: exchangeAddress, value: DEFAULT_PROTOCOL_FEE_PAID.minus(1) },
                 );
                 const expectedError = new StakingRevertErrors.InvalidProtocolFeePaymentError(
-                    StakingRevertErrors.ProtocolFeePaymentErrorCodes.MismatchedFeeAndPayment,
                     DEFAULT_PROTOCOL_FEE_PAID,
                     DEFAULT_PROTOCOL_FEE_PAID.minus(1),
                 );
@@ -143,7 +126,6 @@ blockchainTests('Protocol Fees unit tests', env => {
                     { from: exchangeAddress, value: DEFAULT_PROTOCOL_FEE_PAID.plus(1) },
                 );
                 const expectedError = new StakingRevertErrors.InvalidProtocolFeePaymentError(
-                    StakingRevertErrors.ProtocolFeePaymentErrorCodes.MismatchedFeeAndPayment,
                     DEFAULT_PROTOCOL_FEE_PAID,
                     DEFAULT_PROTOCOL_FEE_PAID.plus(1),
                 );
diff --git a/packages/order-utils/CHANGELOG.json b/packages/order-utils/CHANGELOG.json
index aaa6645a01..9cdec9e65e 100644
--- a/packages/order-utils/CHANGELOG.json
+++ b/packages/order-utils/CHANGELOG.json
@@ -113,6 +113,10 @@
             {
                 "note": "Renamed `OnlyCallableByPoolOperatorOrMakerError` to `OnlyCallableByPoolOperatorError`.",
                 "pr": 2250
+            },
+            {
+                "note": "Removed protocol fee != 0 error.",
+                "pr": 2278
             }
         ],
         "timestamp": 1570135330
diff --git a/packages/order-utils/src/staking_revert_errors.ts b/packages/order-utils/src/staking_revert_errors.ts
index 8debcffe8e..81c0c983ee 100644
--- a/packages/order-utils/src/staking_revert_errors.ts
+++ b/packages/order-utils/src/staking_revert_errors.ts
@@ -14,11 +14,6 @@ export enum OperatorShareErrorCodes {
     CanOnlyDecreaseOperatorShare,
 }
 
-export enum ProtocolFeePaymentErrorCodes {
-    ZeroProtocolFeePaid,
-    MismatchedFeeAndPayment,
-}
-
 export enum InvalidParamValueErrorCodes {
     InvalidCobbDouglasAlpha,
     InvalidRewardDelegatedStakeWeight,
@@ -144,14 +139,13 @@ export class InvalidParamValueError extends RevertError {
 
 export class InvalidProtocolFeePaymentError extends RevertError {
     constructor(
-        errorCode?: ProtocolFeePaymentErrorCodes,
         expectedProtocolFeePaid?: BigNumber | number | string,
         actualProtocolFeePaid?: BigNumber | number | string,
     ) {
         super(
             'InvalidProtocolFeePaymentError',
-            'InvalidProtocolFeePaymentError(uint8 errorCode, uint256 expectedProtocolFeePaid, uint256 actualProtocolFeePaid)',
-            { errorCode, expectedProtocolFeePaid, actualProtocolFeePaid },
+            'InvalidProtocolFeePaymentError(uint256 expectedProtocolFeePaid, uint256 actualProtocolFeePaid)',
+            { expectedProtocolFeePaid, actualProtocolFeePaid },
         );
     }
 }