diff --git a/codex/contracts/market.nim b/codex/contracts/market.nim
index 1a8445f6..fdcebece 100644
--- a/codex/contracts/market.nim
+++ b/codex/contracts/market.nim
@@ -23,6 +23,9 @@ func new*(_: type OnChainMarket, contract: Storage): OnChainMarket =
     signer: signer,
   )
 
+method getSigner*(market: OnChainMarket): Future[Address] {.async.} =
+  return await market.signer.getAddress()
+
 method requestStorage(market: OnChainMarket,
                       request: StorageRequest):
                      Future[StorageRequest] {.async.} =
diff --git a/codex/market.nim b/codex/market.nim
index 91a19299..c8b3f5d8 100644
--- a/codex/market.nim
+++ b/codex/market.nim
@@ -15,6 +15,9 @@ type
   OnRequest* = proc(id: array[32, byte], ask: StorageAsk) {.gcsafe, upraises:[].}
   OnFulfillment* = proc(requestId: array[32, byte]) {.gcsafe, upraises: [].}
 
+method getSigner*(market: Market): Future[Address] {.base, async.} =
+  raiseAssert("not implemented")
+
 method requestStorage*(market: Market,
                        request: StorageRequest):
                       Future[StorageRequest] {.base, async.} =
diff --git a/tests/codex/helpers/mockmarket.nim b/tests/codex/helpers/mockmarket.nim
index 4e534ba3..0b782e9f 100644
--- a/tests/codex/helpers/mockmarket.nim
+++ b/tests/codex/helpers/mockmarket.nim
@@ -7,6 +7,7 @@ type
   MockMarket* = ref object of Market
     requested*: seq[StorageRequest]
     fulfilled*: seq[Fulfillment]
+    signer: Address
     subscriptions: Subscriptions
   Fulfillment* = object
     requestId: array[32, byte]
@@ -23,6 +24,12 @@ type
     requestId: array[32, byte]
     callback: OnFulfillment
 
+proc new*(_: type MockMarket): MockMarket =
+  MockMarket(signer: Address.example)
+
+method getSigner*(market: MockMarket): Future[Address] {.async.} =
+  return market.signer
+
 method requestStorage*(market: MockMarket,
                        request: StorageRequest):
                       Future[StorageRequest] {.async.} =
@@ -58,7 +65,7 @@ proc fulfillRequest*(market: MockMarket,
 method fulfillRequest*(market: MockMarket,
                        requestId: array[32, byte],
                        proof: seq[byte]) {.async.} =
-  market.fulfillRequest(requestid, proof, Address.default)
+  market.fulfillRequest(requestid, proof, market.signer)
 
 method subscribeRequests*(market: MockMarket,
                           callback: OnRequest):
diff --git a/tests/contracts/testMarket.nim b/tests/contracts/testMarket.nim
index 9f75e286..613309e8 100644
--- a/tests/contracts/testMarket.nim
+++ b/tests/contracts/testMarket.nim
@@ -38,6 +38,9 @@ ethersuite "On-Chain Market":
     expect AssertionError:
       discard OnChainMarket.new(storageWithoutSigner)
 
+  test "knows signer address":
+    check (await market.getSigner()) == (await provider.getSigner().getAddress())
+
   test "supports storage requests":
     await token.approve(storage.address, request.ask.maxPrice)
     check (await market.requestStorage(request)) == request