diff --git a/codex/conf.nim b/codex/conf.nim
index 38a24b7f..9ac7a7fc 100644
--- a/codex/conf.nim
+++ b/codex/conf.nim
@@ -295,10 +295,8 @@ type
 
       payoutAddress* {.
         desc: "Address to send reward payouts to"
-        defaultValue: EthAddress.none
-        defaultValueDesc: "Rewards will be sent to the SP's address (derived from --eth-private-key)"
         name: "payout-address"
-      .}: Option[EthAddress]
+      .}: EthAddress
 
       case persistenceCmd* {.
         defaultValue: noCmd
diff --git a/codex/contracts/market.nim b/codex/contracts/market.nim
index 513ef207..2420d44b 100644
--- a/codex/contracts/market.nim
+++ b/codex/contracts/market.nim
@@ -19,7 +19,7 @@ type
   OnChainMarket* = ref object of Market
     contract: Marketplace
     signer: Signer
-    payoutAddress: ?Address
+    payoutAddress: Address
   MarketSubscription = market.Subscription
   EventSubscription = ethers.Subscription
   OnChainMarketSubscription = ref object of MarketSubscription
@@ -28,7 +28,7 @@ type
 func new*(
   _: type OnChainMarket,
   contract: Marketplace,
-  payoutAddress = Address.none): OnChainMarket =
+  payoutAddress: Address): OnChainMarket =
 
   without signer =? contract.signer:
     raiseAssert("Marketplace contract should have a signer")
@@ -167,12 +167,9 @@ method fillSlot(market: OnChainMarket,
   convertEthersError:
     await market.approveFunds(collateral)
 
-    var fillSlot: Future[?TransactionResponse]
-    if payoutAddress =? market.payoutAddress:
-      fillSlot = market.contract.fillSlot(requestId, slotIndex, proof, payoutAddress)
-    else:
-      fillSlot = market.contract.fillSlot(requestId, slotIndex, proof)
-    discard await fillSlot.confirm(0)
+    discard await market.contract.fillSlot(
+      requestId, slotIndex, proof, market.payoutAddress
+    ).confirm(0)
 
 method freeSlot*(market: OnChainMarket, slotId: SlotId) {.async.} =
   convertEthersError:
diff --git a/codex/contracts/marketplace.nim b/codex/contracts/marketplace.nim
index 6f4a2e7e..400981cb 100644
--- a/codex/contracts/marketplace.nim
+++ b/codex/contracts/marketplace.nim
@@ -43,7 +43,6 @@ proc slashPercentage*(marketplace: Marketplace): UInt256 {.contract, view.}
 proc minCollateralThreshold*(marketplace: Marketplace): UInt256 {.contract, view.}
 
 proc requestStorage*(marketplace: Marketplace, request: StorageRequest): ?TransactionResponse {.contract.}
-proc fillSlot*(marketplace: Marketplace, requestId: RequestId, slotIndex: UInt256, proof: Groth16Proof): ?TransactionResponse {.contract.}
 proc fillSlot*(marketplace: Marketplace, requestId: RequestId, slotIndex: UInt256, proof: Groth16Proof, payoutAddress: Address): ?TransactionResponse {.contract.}
 proc withdrawFunds*(marketplace: Marketplace, requestId: RequestId): ?TransactionResponse {.contract.}
 proc freeSlot*(marketplace: Marketplace, id: SlotId): ?TransactionResponse {.contract.}
diff --git a/tests/contracts/testContracts.nim b/tests/contracts/testContracts.nim
index 4432160d..5d3a5790 100644
--- a/tests/contracts/testContracts.nim
+++ b/tests/contracts/testContracts.nim
@@ -11,6 +11,7 @@ ethersuite "Marketplace contracts":
   let proof = Groth16Proof.example
 
   var client, host: Signer
+  var payoutAddress: Address
   var marketplace: Marketplace
   var token: Erc20Token
   var periodicity: Periodicity
@@ -24,6 +25,7 @@ ethersuite "Marketplace contracts":
   setup:
     client = ethProvider.getSigner(accounts[0])
     host = ethProvider.getSigner(accounts[1])
+    payoutAddress = accounts[2]
 
     let address = Marketplace.address(dummyVerifier = true)
     marketplace = Marketplace.new(address, ethProvider.getSigner())
@@ -42,7 +44,7 @@ ethersuite "Marketplace contracts":
     discard await marketplace.requestStorage(request)
     switchAccount(host)
     discard await token.approve(marketplace.address, request.ask.collateral)
-    discard await marketplace.fillSlot(request.id, 0.u256, proof)
+    discard await marketplace.fillSlot(request.id, 0.u256, proof, payoutAddress)
     slotId = request.slotId(0.u256)
 
   proc waitUntilProofRequired(slotId: SlotId) {.async.} =
@@ -57,7 +59,7 @@ ethersuite "Marketplace contracts":
   proc startContract() {.async.} =
     for slotIndex in 1..<request.ask.slots:
       discard await token.approve(marketplace.address, request.ask.collateral)
-      discard await marketplace.fillSlot(request.id, slotIndex.u256, proof)
+      discard await marketplace.fillSlot(request.id, slotIndex.u256, proof, payoutAddress)
 
   test "accept marketplace proofs":
     switchAccount(host)
@@ -75,14 +77,18 @@ ethersuite "Marketplace contracts":
 
   test "can be paid out at the end":
     switchAccount(host)
-    let address = await host.getAddress()
+    let hostAddress = await host.getAddress()
     await startContract()
     let requestEnd = await marketplace.requestEnd(request.id)
     await ethProvider.advanceTimeTo(requestEnd.u256 + 1)
-    let startBalance = await token.balanceOf(address)
+    let startBalanceHost = await token.balanceOf(hostAddress)
+    let startBalancePayout = await token.balanceOf(payoutAddress)
     discard await marketplace.freeSlot(slotId)
-    let endBalance = await token.balanceOf(address)
-    check endBalance == (startBalance + request.ask.duration * request.ask.reward + request.ask.collateral)
+    let endBalanceHost = await token.balanceOf(hostAddress)
+    let endBalancePayout = await token.balanceOf(payoutAddress)
+
+    check endBalanceHost == (startBalanceHost + request.ask.collateral)
+    check endBalancePayout == (startBalancePayout + request.ask.duration * request.ask.reward)
 
   test "cannot mark proofs missing for cancelled request":
     let expiry = await marketplace.requestExpiry(request.id)
diff --git a/tests/contracts/testMarket.nim b/tests/contracts/testMarket.nim
index 561c82cd..dde92aab 100644
--- a/tests/contracts/testMarket.nim
+++ b/tests/contracts/testMarket.nim
@@ -17,13 +17,20 @@ ethersuite "On-Chain Market":
   var slotIndex: UInt256
   var periodicity: Periodicity
   var host: Signer
+  var payoutAddress: Address
+
+  proc switchAccount(account: Signer) =
+    marketplace = marketplace.connect(account)
+    token = token.connect(account)
+    market = OnChainMarket.new(marketplace, payoutAddress)
 
   setup:
     let address = Marketplace.address(dummyVerifier = true)
     marketplace = Marketplace.new(address, ethProvider.getSigner())
     let config = await marketplace.config()
+    payoutAddress = accounts[2]
 
-    market = OnChainMarket.new(marketplace)
+    market = OnChainMarket.new(marketplace, payoutAddress)
     let tokenAddress = await marketplace.token()
     token = Erc20Token.new(tokenAddress, ethProvider.getSigner())
 
@@ -31,6 +38,7 @@ ethersuite "On-Chain Market":
 
     request = StorageRequest.example
     request.client = accounts[0]
+    host = ethProvider.getSigner(accounts[1])
 
     slotIndex = (request.ask.slots div 2).u256
 
@@ -53,7 +61,7 @@ ethersuite "On-Chain Market":
   test "fails to instantiate when contract does not have a signer":
     let storageWithoutSigner = marketplace.connect(ethProvider)
     expect AssertionDefect:
-      discard OnChainMarket.new(storageWithoutSigner)
+      discard OnChainMarket.new(storageWithoutSigner, payoutAddress)
 
   test "knows signer address":
     check (await market.getSigner()) == (await ethProvider.getSigner().getAddress())
@@ -360,32 +368,12 @@ ethersuite "On-Chain Market":
       (await market.queryPastStorageRequests(blocksAgo = 2))
     )
 
-  test "pays out to host address, including collateral":
-    let address = request.client
-    await market.requestStorage(request)
-
-    for slotIndex in 0..<request.ask.slots:
-      await market.fillSlot(request.id, slotIndex.u256, proof, request.ask.collateral)
-
-    let requestEnd = await market.getRequestEnd(request.id)
-    await ethProvider.advanceTimeTo(requestEnd.u256 + 1)
-
-    let startBalance = await token.balanceOf(address)
-
-    await market.freeSlot(request.slotId(0.u256))
-
-    let endBalance = await token.balanceOf(address)
-    check endBalance == (startBalance +
-                        request.ask.duration * request.ask.reward +
-                        request.ask.collateral)
-
   test "pays out to payout address, collateral paid to host address":
-    let hostAddress = request.client
-    let hostPayoutAddress = accounts[2]
+    let hostAddress = await host.getAddress()
 
-    market = OnChainMarket.new(marketplace, hostPayoutAddress.some)
     await market.requestStorage(request)
 
+    switchAccount(host)
     for slotIndex in 0..<request.ask.slots:
       await market.fillSlot(request.id, slotIndex.u256, proof, request.ask.collateral)
 
@@ -393,14 +381,13 @@ ethersuite "On-Chain Market":
     await ethProvider.advanceTimeTo(requestEnd.u256 + 1)
 
     let startBalanceHost = await token.balanceOf(hostAddress)
-    let startBalanceHostPayout = await token.balanceOf(hostPayoutAddress)
+    let startBalancePayout = await token.balanceOf(payoutAddress)
 
     await market.freeSlot(request.slotId(0.u256))
 
     let endBalanceHost = await token.balanceOf(hostAddress)
-    let endBalanceHostPayout = await token.balanceOf(hostPayoutAddress)
+    let endBalancePayout = await token.balanceOf(payoutAddress)
 
-    check endBalanceHostPayout == (startBalanceHostPayout +
-                                  request.ask.duration * request.ask.reward)
-    check endBalanceHost == (startBalanceHost +
-                            request.ask.collateral)
+    check endBalanceHost == (startBalanceHost + request.ask.collateral)
+    check endBalancePayout == (startBalancePayout +
+                               request.ask.duration * request.ask.reward)
diff --git a/vendor/codex-contracts-eth b/vendor/codex-contracts-eth
index be76f404..6db5479c 160000
--- a/vendor/codex-contracts-eth
+++ b/vendor/codex-contracts-eth
@@ -1 +1 @@
-Subproject commit be76f4042aafad65c8a303382fa302f8d775b10b
+Subproject commit 6db5479c855ff9048c6557aa7966a40d308492b4