diff --git a/spago.dhall b/spago.dhall
index eb92449..1da3b1d 100644
--- a/spago.dhall
+++ b/spago.dhall
@@ -8,7 +8,6 @@
   , "control"
   , "coroutine-transducers"
   , "coroutines"
-  , "debug"
   , "effect"
   , "either"
   , "errors"
@@ -28,7 +27,6 @@
   , "partial"
   , "prelude"
   , "profunctor-lenses"
-  , "quickcheck"
   , "record"
   , "ring-modules"
   , "simple-json"
diff --git a/src/Network/Ethereum/Web3/Solidity/Bytes.purs b/src/Network/Ethereum/Web3/Solidity/Bytes.purs
index bb558a1..1afae38 100644
--- a/src/Network/Ethereum/Web3/Solidity/Bytes.purs
+++ b/src/Network/Ethereum/Web3/Solidity/Bytes.purs
@@ -14,7 +14,7 @@ import Data.ByteString (empty, ByteString, Encoding(Hex))
 import Data.ByteString as BS
 import Data.Maybe (Maybe(..), fromJust)
 import Data.Reflectable (class Reflectable, reflectType)
-import Network.Ethereum.Core.HexString (genBytes, toByteString)
+import Network.Ethereum.Core.HexString as Hex
 import Network.Ethereum.Types (mkHexString)
 import Partial.Unsafe (unsafePartial)
 import Type.Proxy (Proxy(..))
@@ -32,8 +32,8 @@ instance showBytesN :: Show (BytesN n) where
 
 generator :: forall n m. Reflectable n Int => MonadGen m => Proxy n -> m (BytesN n)
 generator p = do
-  bs <- genBytes (reflectType p)
-  pure $ BytesN $ toByteString bs
+  bs <- Hex.generator (reflectType p)
+  pure $ BytesN $ Hex.toByteString bs
 
 -- | Access the underlying raw bytestring
 unBytesN :: forall n. BytesN n -> ByteString
diff --git a/src/Network/Ethereum/Web3/Solidity/Int.purs b/src/Network/Ethereum/Web3/Solidity/Int.purs
index 9b908b0..dae57e6 100644
--- a/src/Network/Ethereum/Web3/Solidity/Int.purs
+++ b/src/Network/Ethereum/Web3/Solidity/Int.purs
@@ -11,7 +11,7 @@ import Control.Monad.Gen (class MonadGen)
 import Data.Maybe (Maybe(..), fromJust)
 import Data.Reflectable (class Reflectable, reflectType)
 import Network.Ethereum.Core.BigNumber (BigNumber, embed, fromString, fromTwosComplement, pow)
-import Network.Ethereum.Core.HexString (genBytes, unHex)
+import Network.Ethereum.Core.HexString as Hex
 import Partial.Unsafe (unsafePartial)
 import Type.Proxy (Proxy(..))
 
@@ -28,11 +28,11 @@ derive newtype instance ordIntN :: Ord (IntN n)
 
 generator :: forall n m. Reflectable n Int => MonadGen m => Proxy n -> m (IntN n)
 generator p = do
-  bs <- genBytes (reflectType p `div` 8)
+  bs <- Hex.generator (reflectType p `div` 8)
   let
     a =
       if bs == mempty then zero
-      else unsafePartial $ fromJust $ fromString $ unHex $ bs
+      else unsafePartial $ fromJust $ fromString $ Hex.unHex $ bs
   pure $ IntN $ fromTwosComplement (reflectType (Proxy @n)) a
 
 -- | Access the raw underlying integer
diff --git a/src/Network/Ethereum/Web3/Solidity/UInt.purs b/src/Network/Ethereum/Web3/Solidity/UInt.purs
index d96699a..494812a 100644
--- a/src/Network/Ethereum/Web3/Solidity/UInt.purs
+++ b/src/Network/Ethereum/Web3/Solidity/UInt.purs
@@ -11,7 +11,7 @@ import Control.Monad.Gen (class MonadGen, chooseInt)
 import Data.Maybe (Maybe(..), fromJust)
 import Data.Reflectable (class Reflectable, reflectType)
 import Network.Ethereum.Core.BigNumber (BigNumber, embed, fromString, pow)
-import Network.Ethereum.Core.HexString (genBytes, unHex)
+import Network.Ethereum.Core.HexString as Hex
 import Partial.Unsafe (unsafePartial)
 import Test.QuickCheck (class Arbitrary)
 import Test.QuickCheck.Gen as Gen
@@ -36,21 +36,21 @@ generator
   -> m (UIntN n)
 generator p = do
   nBytes <- (flip div 8) <$> chooseInt 1 (reflectType p)
-  bs <- genBytes nBytes
+  bs <- Hex.generator nBytes
   let
     a =
       if bs == mempty then zero
-      else unsafePartial $ fromJust $ fromString $ unHex bs
+      else unsafePartial $ fromJust $ fromString $ Hex.unHex bs
   pure $ UIntN $ if a < zero then -a else a
 
 instance Reflectable n Int => Arbitrary (UIntN n) where
   arbitrary = do
     nBytes <- (flip div 8) <$> Gen.chooseInt 1 (reflectType (Proxy @n))
-    bs <- genBytes nBytes
+    bs <- Hex.generator nBytes
     let
       a =
         if bs == mempty then zero
-        else unsafePartial $ fromJust $ fromString $ unHex bs
+        else unsafePartial $ fromJust $ fromString $ Hex.unHex bs
     pure $ UIntN $ if a < zero then -a else a
 
 -- | Access the raw underlying unsigned integer
diff --git a/test.dhall b/test.dhall
index 4dd447d..c0a2cfc 100644
--- a/test.dhall
+++ b/test.dhall
@@ -14,5 +14,6 @@ in    conf
             , "identity"
             , "enums"
             , "integers"
+            , "quickcheck"
             ]
       }
diff --git a/test/web3/Web3Spec/Encoding/ContainersSpec.purs b/test/web3/Web3Spec/Encoding/ContainersSpec.purs
index afd7d95..5134105 100644
--- a/test/web3/Web3Spec/Encoding/ContainersSpec.purs
+++ b/test/web3/Web3Spec/Encoding/ContainersSpec.purs
@@ -17,7 +17,8 @@ import Data.Reflectable (reifyType)
 import Data.String (CodePoint, fromCodePointArray)
 import Data.Tuple (Tuple(..))
 import Effect.Class (liftEffect)
-import Network.Ethereum.Core.HexString (genBytes, toByteString)
+import Network.Ethereum.Core.HexString as Hex
+import Network.Ethereum.Core.Signatures as Address
 import Network.Ethereum.Web3.Solidity (class GenericABIDecode, class GenericABIEncode, Tuple4(..), Tuple5(..), genericABIEncode, genericFromData)
 import Network.Ethereum.Web3.Solidity.AbiEncoding (class ABIEncode, class ABIDecode, toDataBuilder, fromData)
 import Network.Ethereum.Web3.Solidity.Bytes as BytesN
@@ -25,7 +26,6 @@ import Network.Ethereum.Web3.Solidity.EncodingType (class EncodingType)
 import Network.Ethereum.Web3.Solidity.Int as IntN
 import Network.Ethereum.Web3.Solidity.UInt as UIntN
 import Network.Ethereum.Web3.Solidity.Vector as Vector
-import Network.Ethereum.Web3.Types (Address, HexString)
 import Parsing (ParseError)
 import Partial.Unsafe (unsafePartial)
 import Test.QuickCheck (class Arbitrary, arbitrary, quickCheck, quickCheckGen, (===))
@@ -48,17 +48,18 @@ typePropertyTests =
       quickCheck \(x :: BMPString) -> (encodeDecode x) === Right x
 
     it "can encode/decode bytestring" $ liftEffect $ do
-      quickCheck \(_x :: HexString) ->
-        let
-          x = toByteString _x
-        in
-          (encodeDecode x) === Right x
+      quickCheckGen $ do
+        n <- chooseInt 1 100
+        x <- Hex.toByteString <$> Hex.generator n
+        pure $ encodeDecode x === Right x
 
     it "can encode/decode bool" $ liftEffect $ do
       quickCheck \(x :: Boolean) -> encodeDecode x === Right x
 
     it "can encode/decode address" $ liftEffect $ do
-      quickCheck \(x :: Address) -> encodeDecode x === Right x
+      quickCheckGen $ do
+        x <- Address.generator
+        pure $ encodeDecode x === Right x
 
     it "can encode/decode intN" $ liftEffect $ do
       for_ intSizes $ \n -> quickCheckGen $ do
@@ -105,7 +106,9 @@ arrayTypePropertyTests = do
           pure $ encodeDecode x === Right x
 
     it "Can encode/decode address[]" $ liftEffect do
-      quickCheck $ \(x :: Address) -> encodeDecode x === Right x
+      quickCheckGen $ do
+        x <- Address.generator
+        pure $ encodeDecode x === Right x
 
     it "Can encode/decode string[]" $ liftEffect do
       quickCheck $ \(x :: Array BMPString) ->
@@ -147,7 +150,7 @@ vecTypePropertyTests = do
       quickCheckGen $ do
         k <- chooseInt 1 10
         reifyType k \pk -> do
-          x <- Vector.generator pk (arbitrary :: Gen Address)
+          x <- Vector.generator pk Address.generator
           pure $ encodeDecode x === Right x
 
     it "Can encode/decode string[k]" $ liftEffect do
@@ -243,7 +246,7 @@ tupleTests = do
           reifyType m \pm ->
             reifyType k \pk -> do
               int <- IntN.generator pn
-              addr <- arbitrary :: Gen Address
+              addr <- Address.generator
               bool <- arbitrary :: Gen Boolean
               uint <- UIntN.generator pm
               bytes <- BytesN.generator pk
@@ -260,7 +263,7 @@ tupleTests = do
           reifyType k2 \pk2 ->
             reifyType n \pn -> do
               reifyType m \pm -> do
-                addrs <- arrayOf (Vector.generator pk1 (arbitrary @Address))
+                addrs <- arrayOf (Vector.generator pk1 Address.generator)
                 bool <- arbitrary @Boolean
                 ints <- Vector.generator pk2 (IntN.generator pn)
                 uint <- (UIntN.generator pm)
@@ -278,8 +281,8 @@ tupleTests = do
           reifyType m \pm ->
             reifyType k \pk -> do
               ints <- arrayOf (IntN.generator pn)
-              bytes <- toByteString <$> (chooseInt 1 100 >>= genBytes)
-              addrs <- Vector.generator pm (arrayOf $ arbitrary @Address)
+              bytes <- Hex.toByteString <$> (chooseInt 1 100 >>= Hex.generator)
+              addrs <- Vector.generator pm (arrayOf Address.generator)
               strings <- arrayOf (Vector.generator pk (arbitrary @BMPString))
               bool <- arbitrary :: Gen Boolean
               let x = Tuple5 ints bytes addrs strings bool
@@ -295,7 +298,7 @@ tupleTests = do
           reifyType k2 \pk2 ->
             reifyType n \pn -> do
               reifyType m \pm -> do
-                addrs <- arrayOf (Vector.generator pk1 (arbitrary @Address))
+                addrs <- arrayOf (Vector.generator pk1 Address.generator)
                 bool <- arbitrary @Boolean
                 ints <- Vector.generator pk2 (IntN.generator pn)
                 uint <- (UIntN.generator pm)
diff --git a/test/web3/Web3Spec/Encoding/DataSpec.purs b/test/web3/Web3Spec/Encoding/DataSpec.purs
index 9373710..80cd4b9 100644
--- a/test/web3/Web3Spec/Encoding/DataSpec.purs
+++ b/test/web3/Web3Spec/Encoding/DataSpec.purs
@@ -5,12 +5,14 @@ import Prelude
 import Data.Functor.Tagged (Tagged, tagged)
 import Effect.Class (liftEffect)
 import Network.Ethereum.Core.Keccak256 (toSelector)
+import Network.Ethereum.Core.Signatures as Address
 import Network.Ethereum.Web3.Contract (sendTx, mkDataField)
 import Network.Ethereum.Web3.Solidity (Tuple2, UIntN)
 import Network.Ethereum.Web3.Solidity.AbiEncoding (toDataBuilder)
 import Network.Ethereum.Web3.Solidity.Generic (genericFromRecordFields)
+import Network.Ethereum.Web3.Solidity.UInt as UIntN
 import Network.Ethereum.Web3.Types (Address, HexString, NoPay, TransactionOptions, Web3)
-import Test.QuickCheck (quickCheck, (===))
+import Test.QuickCheck (quickCheckGen, (===))
 import Test.Spec (Spec, describe, it)
 import Type.Proxy (Proxy(..))
 
@@ -18,15 +20,15 @@ spec :: Spec Unit
 spec =
   describe "data maker" do
     it "can make the approval data" $ liftEffect do
-      quickCheck $ \(args :: { _spender :: Address, _value :: UIntN 256 }) ->
+      quickCheckGen do
+        args <- { _spender: _, _value: _ } <$> Address.generator <*> UIntN.generator (Proxy @256)
         let
           approvalD = mkDataField (Proxy :: Proxy ApproveFn) args
 
           sel = toSelector "approve(address,uint256)"
 
           fullDat = sel <> toDataBuilder args._spender <> toDataBuilder args._value
-        in
-          approvalD === fullDat
+        pure $ approvalD === fullDat
 
 type ApproveFn = Tagged "approve(address,uint256)" (Tuple2 (Tagged "_spender" Address) (Tagged "_value" (UIntN 256)))