diff --git a/lib/src/main/java/graphql/nadel/schema/NadelDirectives.kt b/lib/src/main/java/graphql/nadel/schema/NadelDirectives.kt
index 7b030c08c..2f609441e 100644
--- a/lib/src/main/java/graphql/nadel/schema/NadelDirectives.kt
+++ b/lib/src/main/java/graphql/nadel/schema/NadelDirectives.kt
@@ -11,6 +11,7 @@ import graphql.language.DirectiveDefinition.newDirectiveDefinition
 import graphql.language.EnumTypeDefinition.newEnumTypeDefinition
 import graphql.language.EnumValueDefinition.newEnumValueDefinition
 import graphql.language.InputObjectTypeDefinition.newInputObjectDefinition
+import graphql.language.ObjectValue
 import graphql.language.StringValue
 import graphql.language.Value
 import graphql.nadel.dsl.FieldMappingDefinition
@@ -33,7 +34,6 @@ import graphql.nadel.util.onInterface
 import graphql.nadel.util.onObject
 import graphql.nadel.util.onScalar
 import graphql.nadel.util.onUnion
-import graphql.scalars.`object`.JsonScalar
 import graphql.schema.GraphQLAppliedDirective
 import graphql.schema.GraphQLAppliedDirectiveArgument
 import graphql.schema.GraphQLDirectiveContainer
@@ -41,7 +41,6 @@ import graphql.schema.GraphQLEnumType
 import graphql.schema.GraphQLFieldDefinition
 import graphql.schema.GraphQLSchema
 import java.util.Locale
-import kotlin.reflect.typeOf
 
 /**
  * If you update this file please add to NadelBuiltInTypes
@@ -255,8 +254,7 @@ object NadelDirectives {
         val hydrations = fieldDefinition.getAppliedDirectives(hydratedDirectiveDefinition.name)
             .asSequence()
             .map { directive ->
-                val argumentValues = resolveArgumentValue<List<Any>>(directive.getArgument("arguments"))
-                val arguments = createRemoteArgs(argumentValues)
+                val arguments = createRemoteArgs(directive.getArgument("arguments").argumentValue.value as ArrayValue)
 
                 val inputIdentifiedBy = directive.getArgument("inputIdentifiedBy")
                 val identifiedByValues = resolveArgumentValue<List<Any>>(inputIdentifiedBy)
@@ -334,20 +332,20 @@ object NadelDirectives {
         )
     }
 
-    private fun createRemoteArgs(arguments: List<Any>): List<RemoteArgumentDefinition> {
+    private fun createRemoteArgs(arguments: ArrayValue): List<RemoteArgumentDefinition> {
         fun Map<String, String>.requireArgument(key: String): String {
             return requireNotNull(this[key]) {
                 "${nadelHydrationArgumentDefinition.name} definition requires '$key' to be not-null"
             }
         }
 
-        return arguments
+        return arguments.values
             .map { arg ->
                 @Suppress("UNCHECKED_CAST") // trust GraphQL type system and caller
-                val argMap = arg as Map<String, String>
-                val remoteArgName = argMap.requireArgument("name")
-                val remoteArgValue = argMap.requireArgument("value")
-                val remoteArgumentSource = createRemoteArgumentSource(StringValue(remoteArgValue))
+                val argMap = arg as ObjectValue
+                val remoteArgName = (argMap.objectFields.single { it.name == "name" }.value as StringValue).value
+                val remoteArgValue = argMap.objectFields.single { it.name == "value" }.value
+                val remoteArgumentSource = createRemoteArgumentSource(remoteArgValue)
                 RemoteArgumentDefinition(remoteArgName, remoteArgumentSource)
             }
     }
diff --git a/lib/src/main/java/graphql/nadel/schema/NeverWiringFactory.kt b/lib/src/main/java/graphql/nadel/schema/NeverWiringFactory.kt
index 2bf4d5add..d8522616d 100644
--- a/lib/src/main/java/graphql/nadel/schema/NeverWiringFactory.kt
+++ b/lib/src/main/java/graphql/nadel/schema/NeverWiringFactory.kt
@@ -1,6 +1,7 @@
 package graphql.nadel.schema
 
 import graphql.Assert.assertShouldNeverHappen
+import graphql.scalars.ExtendedScalars
 import graphql.schema.Coercing
 import graphql.schema.DataFetcher
 import graphql.schema.GraphQLScalarType
@@ -24,6 +25,9 @@ open class NeverWiringFactory : WiringFactory {
 
     override fun getScalar(environment: ScalarWiringEnvironment): GraphQLScalarType? {
         val scalarName = environment.scalarTypeDefinition.name
+        if (scalarName == ExtendedScalars.Json.name){
+            return ExtendedScalars.Json
+        }
         return GraphQLScalarType
             .newScalar()
             .name(scalarName)
diff --git a/lib/src/main/java/graphql/nadel/schema/OverallSchemaGenerator.kt b/lib/src/main/java/graphql/nadel/schema/OverallSchemaGenerator.kt
index ffc49aef8..29bd4be9f 100644
--- a/lib/src/main/java/graphql/nadel/schema/OverallSchemaGenerator.kt
+++ b/lib/src/main/java/graphql/nadel/schema/OverallSchemaGenerator.kt
@@ -4,6 +4,7 @@ import graphql.GraphQLException
 import graphql.language.FieldDefinition
 import graphql.language.ObjectTypeDefinition
 import graphql.language.ObjectTypeDefinition.newObjectTypeDefinition
+import graphql.language.ScalarTypeDefinition.newScalarTypeDefinition
 import graphql.language.SchemaDefinition
 import graphql.language.SourceLocation
 import graphql.nadel.NadelDefinitionRegistry
@@ -12,6 +13,7 @@ import graphql.nadel.util.AnyNamedNode
 import graphql.nadel.util.AnySDLDefinition
 import graphql.nadel.util.AnySDLNamedDefinition
 import graphql.nadel.util.isExtensionDef
+import graphql.scalars.ExtendedScalars
 import graphql.schema.GraphQLSchema
 import graphql.schema.idl.RuntimeWiring
 import graphql.schema.idl.SchemaGenerator
@@ -70,6 +72,9 @@ internal class OverallSchemaGenerator {
         addIfNotPresent(overallRegistry, allDefinitions, NadelDirectives.nadelHydrationTemplateEnumDefinition)
         addIfNotPresent(overallRegistry, allDefinitions, NadelDirectives.hydratedFromDirectiveDefinition)
         addIfNotPresent(overallRegistry, allDefinitions, NadelDirectives.hydratedTemplateDirectiveDefinition)
+        addIfNotPresent(overallRegistry, allDefinitions, newScalarTypeDefinition()
+            .name(ExtendedScalars.Json.name)
+            .build())
 
         for (definition in allDefinitions) {
             val error = overallRegistry.add(definition)
diff --git a/lib/src/test/kotlin/graphql/nadel/schema/NadelDirectivesTest.kt b/lib/src/test/kotlin/graphql/nadel/schema/NadelDirectivesTest.kt
index 32a43ace2..f057b25b7 100644
--- a/lib/src/test/kotlin/graphql/nadel/schema/NadelDirectivesTest.kt
+++ b/lib/src/test/kotlin/graphql/nadel/schema/NadelDirectivesTest.kt
@@ -10,7 +10,8 @@ import graphql.nadel.schema.NadelDirectives.nadelHydrationComplexIdentifiedBy
 import graphql.nadel.schema.NadelDirectives.nadelHydrationFromArgumentDefinition
 import graphql.nadel.schema.NadelDirectives.nadelHydrationTemplateEnumDefinition
 import graphql.schema.GraphQLSchema
-import graphql.schema.idl.RuntimeWiring.MOCKED_WIRING
+import graphql.schema.idl.MockedWiringFactory
+import graphql.schema.idl.RuntimeWiring
 import graphql.schema.idl.SchemaGenerator
 import graphql.schema.idl.SchemaParser
 import io.kotest.core.spec.style.DescribeSpec
@@ -29,11 +30,14 @@ class NadelDirectivesTest : DescribeSpec({
         ${AstPrinter.printAst(nadelHydrationTemplateEnumDefinition)}
         ${AstPrinter.printAst(hydratedFromDirectiveDefinition)}
         ${AstPrinter.printAst(hydratedTemplateDirectiveDefinition)}
+        scalar JSON
     """
 
     fun getSchema(schemaText: String): GraphQLSchema {
         val typeDefs = SchemaParser().parse(commonDefs + "\n" + schemaText)
-        return SchemaGenerator().makeExecutableSchema(typeDefs, MOCKED_WIRING)
+        return SchemaGenerator().makeExecutableSchema(typeDefs, RuntimeWiring
+            .newRuntimeWiring()
+            .wiringFactory(NeverWiringFactory()).build())
     }
 
     describe("@hydrated") {