diff --git a/src/Language/GraphQL/Serialize.hs b/src/Language/GraphQL/Serialize.hs
index 38a7ec7..cad4f47 100644
--- a/src/Language/GraphQL/Serialize.hs
+++ b/src/Language/GraphQL/Serialize.hs
@@ -49,9 +49,9 @@ instance Serialize JSON where
     serialize _ _ = Nothing
     null = JSON Aeson.Null
 
-instance VariableValue Aeson.Value where
-    coerceVariableValue _ Aeson.Null = Just Type.Null
-    coerceVariableValue (In.ScalarBaseType scalarType) value
+instance VariableValue JSON where
+    coerceVariableValue _ (JSON Aeson.Null) = Just Type.Null
+    coerceVariableValue (In.ScalarBaseType scalarType) (JSON value)
         | (Aeson.String stringValue) <- value = Just $ Type.String stringValue
         | (Aeson.Bool booleanValue) <- value = Just $ Type.Boolean booleanValue
         | (Aeson.Number numberValue) <- value
@@ -59,9 +59,9 @@ instance VariableValue Aeson.Value where
             Just $ Type.Float $ toRealFloat numberValue
         | (Aeson.Number numberValue) <- value = -- ID or Int
             Type.Int <$> toBoundedInteger numberValue
-    coerceVariableValue (In.EnumBaseType _) (Aeson.String stringValue) =
+    coerceVariableValue (In.EnumBaseType _) (JSON (Aeson.String stringValue)) =
         Just $ Type.Enum stringValue
-    coerceVariableValue (In.InputObjectBaseType objectType) value
+    coerceVariableValue (In.InputObjectBaseType objectType) (JSON value)
         | (Aeson.Object objectValue) <- value = do
             let (In.InputObjectType _ _ inputFields) = objectType
             (newObjectValue, resultMap) <- foldWithKey objectValue inputFields
@@ -86,16 +86,17 @@ instance VariableValue Aeson.Value where
                 newObjectValue = KeyMap.delete fieldKey objectValue
              in case KeyMap.lookup fieldKey objectValue of
                     Just variableValue -> do
-                        coerced <- coerceVariableValue fieldType variableValue
+                        coerced <- coerceVariableValue fieldType
+                            $ JSON variableValue
                         pure (newObjectValue, insert coerced)
                     Nothing -> Just (objectValue, resultMap)
-    coerceVariableValue (In.ListBaseType listType) value
+    coerceVariableValue (In.ListBaseType listType) (JSON value)
         | (Aeson.Array arrayValue) <- value =
             Type.List <$> foldr foldVector (Just []) arrayValue
-        | otherwise = coerceVariableValue listType value
+        | otherwise = coerceVariableValue listType $ JSON value
       where
         foldVector _ Nothing = Nothing
         foldVector variableValue (Just list) = do
-            coerced <- coerceVariableValue listType variableValue
+            coerced <- coerceVariableValue listType $ JSON variableValue
             pure $ coerced : list 
     coerceVariableValue _ _ = Nothing