diff --git a/ethers/providers/jsonrpc/looping.nim b/ethers/providers/jsonrpc/looping.nim
index f0bb7a8..31a8957 100644
--- a/ethers/providers/jsonrpc/looping.nim
+++ b/ethers/providers/jsonrpc/looping.nim
@@ -2,5 +2,5 @@ template untilCancelled*(body) =
   try:
     while true:
       body
-  except CancelledError:
-    raise
+  except CancelledError as exc:
+    raise exc
diff --git a/ethers/providers/jsonrpc/subscriptions.nim b/ethers/providers/jsonrpc/subscriptions.nim
index 142c9cc..d919f3c 100644
--- a/ethers/providers/jsonrpc/subscriptions.nim
+++ b/ethers/providers/jsonrpc/subscriptions.nim
@@ -14,6 +14,14 @@ type
     callbacks: Table[JsonNode, SubscriptionCallback]
   SubscriptionCallback = proc(id, arguments: JsonNode) {.gcsafe, raises:[].}
 
+# FIXME Nim 1.6.XX seems to have issues tracking exception effects and will see
+#   ghost unlisted Exceptions with table operations. In a smaller example
+#   (https://forum.nim-lang.org/t/10749), using {.experimental:"strictEffects".}
+#   would fix it, but it doesn't work here for some reason I yet don't
+#   understand. For now, therefore, I'm simply using a mitigation which is to
+#   tell the compiler the truth.
+template mitigateEffectsBug(body) = {.cast(raises: []).}: body
+
 method subscribeBlocks*(subscriptions: JsonRpcSubscriptions,
                         onBlock: BlockHandler):
                        Future[JsonNode]
@@ -70,7 +78,7 @@ method subscribeBlocks(subscriptions: WebSocketSubscriptions,
     if blck =? Block.fromJson(arguments["result"]).catch:
       onBlock(blck)
   let id = await subscriptions.client.eth_subscribe("newHeads")
-  subscriptions.callbacks[id] = callback
+  mitigateEffectsBug: subscriptions.callbacks[id] = callback
   return id
 
 method subscribeLogs(subscriptions: WebSocketSubscriptions,
@@ -82,13 +90,13 @@ method subscribeLogs(subscriptions: WebSocketSubscriptions,
     if log =? Log.fromJson(arguments["result"]).catch:
       onLog(log)
   let id = await subscriptions.client.eth_subscribe("logs", filter)
-  subscriptions.callbacks[id] = callback
+  mitigateEffectsBug: subscriptions.callbacks[id] = callback
   return id
 
 method unsubscribe(subscriptions: WebSocketSubscriptions,
                    id: JsonNode)
                   {.async.} =
-  subscriptions.callbacks.del(id)
+  mitigateEffectsBug: subscriptions.callbacks.del(id)
   discard await subscriptions.client.eth_unsubscribe(id)
 
 # Polling
@@ -144,7 +152,7 @@ method subscribeBlocks(subscriptions: PollingSubscriptions,
       asyncSpawn getBlock(hash)
 
   let id = await subscriptions.client.eth_newBlockFilter()
-  subscriptions.callbacks[id] = callback
+  mitigateEffectsBug: subscriptions.callbacks[id] = callback
   return id
 
 method subscribeLogs(subscriptions: PollingSubscriptions,
@@ -158,11 +166,11 @@ method subscribeLogs(subscriptions: PollingSubscriptions,
       onLog(log)
 
   let id = await subscriptions.client.eth_newFilter(filter)
-  subscriptions.callbacks[id] = callback
+  mitigateEffectsBug: subscriptions.callbacks[id] = callback
   return id
 
 method unsubscribe(subscriptions: PollingSubscriptions,
                    id: JsonNode)
                   {.async.} =
-  subscriptions.callbacks.del(id)
+  mitigateEffectsBug: subscriptions.callbacks.del(id)
   discard await subscriptions.client.eth_uninstallFilter(id)
diff --git a/ethers/signer.nim b/ethers/signer.nim
index eaca26c..1962055 100644
--- a/ethers/signer.nim
+++ b/ethers/signer.nim
@@ -26,10 +26,12 @@ proc raiseEstimateGasError(
     parent: parent)
   raise e
 
-method provider*(signer: Signer): Provider {.base, gcsafe.} =
+method provider*(signer: Signer):
+    Provider {.base, gcsafe, raises: [CatchableError].} =
   doAssert false, "not implemented"
 
-method getAddress*(signer: Signer): Future[Address] {.base, gcsafe.} =
+method getAddress*(signer: Signer):
+    Future[Address] {.base, gcsafe, raises: [CatchableError].} =
   doAssert false, "not implemented"
 
 method signMessage*(signer: Signer,
@@ -40,7 +42,8 @@ method sendTransaction*(signer: Signer,
                         transaction: Transaction): Future[TransactionResponse] {.base, async.} =
   doAssert false, "not implemented"
 
-method getGasPrice*(signer: Signer): Future[UInt256] {.base, gcsafe.} =
+method getGasPrice*(signer: Signer):
+    Future[UInt256] {.base, gcsafe, raises: [CatchableError].} =
   signer.provider.getGasPrice()
 
 method getTransactionCount*(signer: Signer,
@@ -59,7 +62,8 @@ method estimateGas*(signer: Signer,
   except ProviderError as e:
     raiseEstimateGasError transaction, e
 
-method getChainId*(signer: Signer): Future[UInt256] {.base, gcsafe.} =
+method getChainId*(signer: Signer):
+    Future[UInt256] {.base, gcsafe, raises: [CatchableError].} =
   signer.provider.getChainId()
 
 method getNonce(signer: Signer): Future[UInt256] {.base, gcsafe, async.} =
@@ -74,7 +78,7 @@ method getNonce(signer: Signer): Future[UInt256] {.base, gcsafe, async.} =
 method updateNonce*(
   signer: Signer,
   nonce: UInt256
-) {.base, gcsafe.} =
+) {.base, gcsafe, raises: [CatchableError].} =
 
   without lastSeen =? signer.lastSeenNonce:
     signer.lastSeenNonce = some nonce
@@ -83,7 +87,7 @@ method updateNonce*(
   if nonce > lastSeen:
     signer.lastSeenNonce = some nonce
 
-method decreaseNonce*(signer: Signer) {.base, gcsafe.} =
+method decreaseNonce*(signer: Signer) {.base, gcsafe, raises: [CatchableError].} =
   if lastSeen =? signer.lastSeenNonce and lastSeen > 0:
     signer.lastSeenNonce = some lastSeen - 1
 
@@ -119,10 +123,12 @@ method populateTransaction*(signer: Signer,
       populated.nonce = some(await signer.getNonce())
       try:
         populated.gasLimit = some(await signer.estimateGas(populated))
-      except ProviderError, EstimateGasError:
-        let e = getCurrentException()
+      except ProviderError as exc:
         signer.decreaseNonce()
-        raise e
+        raise exc
+      except EstimateGasError as exc:
+        signer.decreaseNonce()
+        raise exc
 
     else:
       if transaction.nonce.isNone:
diff --git a/ethers/wallet.nim b/ethers/wallet.nim
index 85305f6..045935b 100644
--- a/ethers/wallet.nim
+++ b/ethers/wallet.nim
@@ -54,7 +54,7 @@ proc createRandom*(_: type Wallet, provider: Provider): Wallet =
   result.address = Address.init(result.publicKey.toCanonicalAddress())
   result.provider = some provider
 
-method provider*(wallet: Wallet): Provider =
+method provider*(wallet: Wallet): Provider {.raises: [CatchableError].} =
   without provider =? wallet.provider:
     raiseWalletError "Wallet has no provider"
   provider
diff --git a/testmodule/hardhat.nim b/testmodule/hardhat.nim
index 55bd79f..f5efc83 100644
--- a/testmodule/hardhat.nim
+++ b/testmodule/hardhat.nim
@@ -1,10 +1,12 @@
+import std/os
 import std/json
 import pkg/ethers/basics
 
 type Deployment* = object
   json: JsonNode
 
-const defaultFile = "../testnode/deployment.json"
+const defaultFile = currentSourcePath.parentDir.parentDir /
+  "testnode" / "deployment.json"
 
 ## Reads deployment information from a json file. It expects a file that has
 ## been exported with Hardhat deploy. See also: