graphql-java
diff --git a/‎src/main/java/graphql/schema/SchemaTransformer.java‎
Lines changed: 2 additions & 1 deletion b/‎src/main/java/graphql/schema/SchemaTransformer.java‎
Lines changed: 2 additions & 1 deletion
@@ -5,6 +5,7 @@
 import graphql.PublicApi;
 import graphql.collect.ImmutableKit;
 import graphql.introspection.Introspection;
+import graphql.schema.idl.ScalarInfo;
 import graphql.util.Breadcrumb;
 import graphql.util.NodeAdapter;
 import graphql.util.NodeLocation;
@@ -650,7 +651,7 @@ private static class DummyRoot implements GraphQLSchemaElement {
                     if (additionalTypes.contains(typeMap.get(typeName))) {
                         continue;
                     }
-                    if (typeMap.get(typeName) instanceof GraphQLScalarType) {
+                    if (ScalarInfo.isGraphqlSpecifiedScalar(typeName)) {
                         continue;
                     }
                     extraTypes.add(typeMap.get(typeName));