diff --git a/nitro.nimble b/nitro.nimble
index 983a6dc..b6f62c0 100644
--- a/nitro.nimble
+++ b/nitro.nimble
@@ -5,6 +5,7 @@ description = "Nitro state channels"
 
 requires "nim >= 1.2.6 & < 2.0.0"
 requires "nimcrypto >= 0.5.4 & < 0.6.0"
+requires "questionable >= 0.2.0 & < 0.3.0"
 requires "secp256k1"
 requires "stint"
 requires "stew"
diff --git a/nitro/helpers.nim b/nitro/helpers.nim
deleted file mode 100644
index 1c58b6a..0000000
--- a/nitro/helpers.nim
+++ /dev/null
@@ -1,13 +0,0 @@
-import std/options
-import pkg/stew/results
-
-include ./noerrors
-
-export options
-export results
-
-proc toOption*[T, E](res: Result[T, E]): Option[T] =
-  if res.isOk:
-    res.unsafeGet().some
-  else:
-    T.none
diff --git a/nitro/noerrors.nim b/nitro/noerrors.nim
deleted file mode 100644
index d2becfc..0000000
--- a/nitro/noerrors.nim
+++ /dev/null
@@ -1,8 +0,0 @@
-## Include this file to indicate that your module does not raise Errors.
-## Disables compiler hints about unused declarations in Nim < 1.4.0
-
-when (NimMajor, NimMinor, NimPatch) >= (1, 4, 0):
-  {.push raises:[].}
-else:
-  {.push raises: [Defect].}
-  {.hint[XDeclaredButNotUsed]: off.}
diff --git a/nitro/protocol/abi.nim b/nitro/protocol/abi.nim
index 92e936b..b481c28 100644
--- a/nitro/protocol/abi.nim
+++ b/nitro/protocol/abi.nim
@@ -2,7 +2,7 @@ import pkg/stew/endians2
 import pkg/stint
 import ../types
 
-include ../noerrors
+include questionable/errorban
 
 export types
 
diff --git a/nitro/protocol/channel.nim b/nitro/protocol/channel.nim
index 7e61eff..2136608 100644
--- a/nitro/protocol/channel.nim
+++ b/nitro/protocol/channel.nim
@@ -2,7 +2,7 @@ import pkg/nimcrypto
 import ../types
 import ./abi
 
-include ../noerrors
+include questionable/errorban
 
 export types
 
diff --git a/nitro/protocol/outcome.nim b/nitro/protocol/outcome.nim
index f9889ee..7c419e5 100644
--- a/nitro/protocol/outcome.nim
+++ b/nitro/protocol/outcome.nim
@@ -2,7 +2,7 @@ import pkg/nimcrypto
 import ../types
 import ./abi
 
-include ../noerrors
+include questionable/errorban
 
 export types
 
diff --git a/nitro/protocol/signature.nim b/nitro/protocol/signature.nim
index 75d9059..10ffb09 100644
--- a/nitro/protocol/signature.nim
+++ b/nitro/protocol/signature.nim
@@ -1,13 +1,13 @@
-import std/options
+import pkg/questionable
+import pkg/questionable/results
 import pkg/nimcrypto
 import pkg/secp256k1
 import pkg/stew/byteutils
-import ../helpers
 import ./state
 
-include ../noerrors
+include questionable/errorban
 
-export options
+export questionable
 export toPublicKey
 
 type
@@ -24,7 +24,7 @@ proc random*(_: type PrivateKey): PrivateKey =
 proc `$`*(key: PrivateKey): string =
   key.toHex()
 
-proc parse*(_: type PrivateKey, s: string): Option[PrivateKey] =
+proc parse*(_: type PrivateKey, s: string): ?PrivateKey =
   SkSecretKey.fromHex(s).toOption()
 
 proc sign(key: PrivateKey, data: openArray[byte]): Signature =
@@ -47,10 +47,9 @@ proc `$`*(signature: Signature): string =
   bytes[64] += 27
   bytes.toHex()
 
-proc parse*(_: type Signature, s: string): Option[Signature] =
-  try:
+proc parse*(_: type Signature, s: string): ?Signature =
+  let signature = catch:
     var bytes = array[65, byte].fromHex(s)
     bytes[64] = bytes[64] - 27
-    SkRecoverableSignature.fromRaw(bytes).toOption()
-  except ValueError:
-    Signature.none
+    SkRecoverableSignature.fromRaw(bytes).get()
+  signature.toOption()
diff --git a/nitro/protocol/state.nim b/nitro/protocol/state.nim
index e20d77f..bb3db25 100644
--- a/nitro/protocol/state.nim
+++ b/nitro/protocol/state.nim
@@ -4,7 +4,7 @@ import ./channel
 import ./outcome
 import ./abi
 
-include ../noerrors
+include questionable/errorban
 
 export types
 export channel
diff --git a/nitro/types.nim b/nitro/types.nim
index 0d6032f..2a67084 100644
--- a/nitro/types.nim
+++ b/nitro/types.nim
@@ -1,12 +1,12 @@
 import std/math
-import std/options
+import pkg/questionable
 import pkg/stint
 import pkg/stew/byteutils
 
-include ./noerrors
+include questionable/errorban
 
 export stint
-export options
+export questionable
 
 type
   UInt48* = range[0'u64..2'u64^48-1]
@@ -15,7 +15,7 @@ type
 proc toArray*(address: EthAddress): array[20, byte] =
   array[20, byte](address)
 
-proc fromHex*(_: type EthAddress, hex: string): Option[EthAddress] =
+proc fromHex*(_: type EthAddress, hex: string): ?EthAddress =
   try:
     EthAddress(array[20, byte].fromHex(hex)).some
   except ValueError: