diff --git a/src/Network/Ethereum/Web3/Contract.purs b/src/Network/Ethereum/Web3/Contract.purs
index b2615c3..4b0bb45 100644
--- a/src/Network/Ethereum/Web3/Contract.purs
+++ b/src/Network/Ethereum/Web3/Contract.purs
@@ -159,10 +159,10 @@ deployContract txOptions deployByteCode args =
     eth_sendTransaction txdata
 
 mkDataField
-  :: forall selector a rep fields l
+  :: forall selector a rep fields
    . IsSymbol selector
   => Generic a rep
-  => GRecordFieldsIso rep fields l
+  => GRecordFieldsIso rep fields
   => GenericABIEncode rep
   => Proxy (Tagged selector a)
   -> Record fields
diff --git a/src/Network/Ethereum/Web3/Solidity/Event.purs b/src/Network/Ethereum/Web3/Solidity/Event.purs
index 5f0fa63..14caaab 100644
--- a/src/Network/Ethereum/Web3/Solidity/Event.purs
+++ b/src/Network/Ethereum/Web3/Solidity/Event.purs
@@ -75,11 +75,11 @@ parseChange (Change change) anonymous = do
   pure $ Event a b
 
 combineChange
-  :: forall afields al a arep bfields bl b brep c cfields
+  :: forall afields a arep bfields b brep c cfields
    . Generic a arep
   => Generic b brep
-  => GRecordFieldsIso arep afields al
-  => GRecordFieldsIso brep bfields bl
+  => GRecordFieldsIso arep afields
+  => GRecordFieldsIso brep bfields
   => Row.Union afields bfields cfields
   => Row.Nub cfields cfields
   => Newtype c (Record cfields)
@@ -93,12 +93,12 @@ class IndexedEvent a b c | c -> a b where
   isAnonymous :: Proxy c -> Boolean
 
 decodeEventDef
-  :: forall afields al a arep bfields bl b brep c cfields
+  :: forall afields a arep bfields b brep c cfields
    . Generic a arep
-  => GRecordFieldsIso arep afields al
+  => GRecordFieldsIso arep afields
   => GenericABIDecode arep
   => ArrayParser arep
-  => GRecordFieldsIso brep bfields bl
+  => GRecordFieldsIso brep bfields
   => Generic b brep
   => GenericABIDecode brep
   => Row.Union afields bfields cfields
@@ -122,10 +122,10 @@ class
 
 instance
   ( ArrayParser arep
-  , GRecordFieldsIso arep afields al
+  , GRecordFieldsIso arep afields
   , Generic a arep
   , GenericABIDecode arep
-  , GRecordFieldsIso brep bfields bl
+  , GRecordFieldsIso brep bfields
   , Generic b brep
   , GenericABIDecode brep
   , Row.Union afields bfields cfields
diff --git a/src/Network/Ethereum/Web3/Solidity/Internal.purs b/src/Network/Ethereum/Web3/Solidity/Internal.purs
index 99b0fc0..4fd4818 100644
--- a/src/Network/Ethereum/Web3/Solidity/Internal.purs
+++ b/src/Network/Ethereum/Web3/Solidity/Internal.purs
@@ -14,51 +14,48 @@ import Data.Symbol (class IsSymbol)
 import Prim.Row as Row
 import Record as Record
 import Type.Proxy (Proxy(..))
-import Type.RowList (class RowListAppend, Cons, Nil)
 import Unsafe.Coerce (unsafeCoerce)
 
-class GRecordFieldsIso :: forall k1. Type -> Row Type -> k1 -> Constraint
-class GRecordFieldsIso rep fields k | rep -> k, k -> rep fields where
-  gToRecordFields :: Proxy k -> rep -> Record fields
-  gFromRecordFields :: Proxy k -> Record fields -> rep
+class GRecordFieldsIso rep fields | rep -> fields where
+  gToRecordFields :: rep -> Record fields
+  gFromRecordFields :: Record fields -> rep
 
-instance GRecordFieldsIso NoArguments () Nil where
-  gToRecordFields _ _ = {}
-  gFromRecordFields _ _ = NoArguments
+instance GRecordFieldsIso NoArguments () where
+  gToRecordFields _ = {}
+  gFromRecordFields _ = NoArguments
 
-else instance GRecordFieldsIso a r rl => GRecordFieldsIso (Constructor name a) r (Cons name rl Nil) where
-  gToRecordFields _ (Constructor a) = gToRecordFields (Proxy @rl) a
-  gFromRecordFields _ r = Constructor (gFromRecordFields (Proxy @rl) r)
+else instance GRecordFieldsIso a r => GRecordFieldsIso (Constructor name a) r where
+  gToRecordFields (Constructor a) = gToRecordFields a
+  gFromRecordFields r = Constructor (gFromRecordFields r)
 
 else instance
   ( IsSymbol s
   , Row.Cons s a () r
   , Row.Lacks s ()
   ) =>
-  GRecordFieldsIso (Argument (Tagged s a)) r (Cons s a Nil) where
-  gToRecordFields _ (Argument a) = Record.insert (Proxy @s) (untagged a) {}
-  gFromRecordFields _ r = Argument (tagged $ Record.get (Proxy @s) r)
+  GRecordFieldsIso (Argument (Tagged s a)) r where
+  gToRecordFields (Argument a) = Record.insert (Proxy @s) (untagged a) {}
+  gFromRecordFields r = Argument (tagged $ Record.get (Proxy @s) r)
 
 else instance
-  ( GRecordFieldsIso as ra rla
-  , GRecordFieldsIso bs rb rlb
-  , RowListAppend rla rlb rl
+  ( GRecordFieldsIso as ra
+  , GRecordFieldsIso bs rb
   , Row.Union ra rb r
   , Row.Nub r r
   ) =>
-  GRecordFieldsIso (Product as bs) r rl where
-  gToRecordFields _ (Product as bs) =
-    Record.merge (gToRecordFields (Proxy @rla) as) (gToRecordFields (Proxy @rlb) bs)
+  GRecordFieldsIso (Product as bs) r where
+  gToRecordFields (Product as bs) =
+    Record.merge (gToRecordFields as) (gToRecordFields bs)
 
-  gFromRecordFields _ r =
+  gFromRecordFields r =
     let
-      as = gFromRecordFields (Proxy @rla) (unsafeCoerce r)
-      bs = gFromRecordFields (Proxy @rlb) (unsafeCoerce r)
+      as = gFromRecordFields (unsafeCoerce r)
+      bs = gFromRecordFields (unsafeCoerce r)
     in
       Product as bs
 
-toRecord :: forall a rep fields l. Generic a rep => GRecordFieldsIso rep fields l => a -> Record fields
-toRecord a = gToRecordFields (Proxy :: Proxy l) (from a)
+toRecord :: forall a rep fields. Generic a rep => GRecordFieldsIso rep fields => a -> Record fields
+toRecord a = gToRecordFields $ from a
 
-fromRecord :: forall a rep fields l. Generic a rep => GRecordFieldsIso rep fields l => Record fields -> a
-fromRecord a = to $ gFromRecordFields (Proxy :: Proxy l) a
+fromRecord :: forall a rep fields. Generic a rep => GRecordFieldsIso rep fields => Record fields -> a
+fromRecord a = to $ gFromRecordFields a