diff --git a/src/js_class.hpp b/src/js_class.hpp
index 70b28e2e..4b5f8d7d 100644
--- a/src/js_class.hpp
+++ b/src/js_class.hpp
@@ -28,7 +28,7 @@ namespace realm {
 namespace js {
 
 template<typename T>
-using ConstructorType = void(typename T::Context, typename T::Object, size_t, const typename T::Value[]);
+using ConstructorType = void(typename T::Context, typename T::Function, typename T::Object, size_t, const typename T::Value[]);
 
 template<typename T>
 using MethodType = void(typename T::Context, typename T::Function, typename T::Object, size_t, const typename T::Value[], ReturnValue<T> &);
diff --git a/src/js_realm.hpp b/src/js_realm.hpp
index 5627446a..1cb12208 100644
--- a/src/js_realm.hpp
+++ b/src/js_realm.hpp
@@ -187,7 +187,7 @@ public:
 #endif
 
     // static methods
-    static void constructor(ContextType, ObjectType, size_t, const ValueType[]);
+    static void constructor(ContextType, FunctionType, ObjectType, size_t, const ValueType[]);
     static SharedRealm create_shared_realm(ContextType, realm::Realm::Config, bool, ObjectDefaultsMap &&, ConstructorMap &&);
 
     static void schema_version(ContextType, FunctionType, ObjectType, size_t, const ValueType[], ReturnValue &);
@@ -327,7 +327,7 @@ static inline void convert_outdated_datetime_columns(const SharedRealm &realm) {
 }
 
 template<typename T>
-void RealmClass<T>::constructor(ContextType ctx, ObjectType this_object, size_t argc, const ValueType arguments[]) {
+void RealmClass<T>::constructor(ContextType ctx, FunctionType constructor_function, ObjectType this_object, size_t argc, const ValueType arguments[]) {
     realm::Realm::Config config;
     ObjectDefaultsMap defaults;
     ConstructorMap constructors;
@@ -353,7 +353,7 @@ void RealmClass<T>::constructor(ContextType ctx, ObjectType this_object, size_t
             }
 
 #if REALM_ENABLE_SYNC
-            SyncClass<T>::populate_sync_config(ctx, Value::validated_to_object(ctx, Object::get_property(ctx, this_object, "Sync")), object, config);
+            SyncClass<T>::populate_sync_config(ctx, Value::validated_to_object(ctx, Object::get_property(ctx, constructor_function, "Sync")), object, config);
 #endif
 
             static const String path_string = "path";
diff --git a/src/jsc/jsc_class.hpp b/src/jsc/jsc_class.hpp
index 6e6f7618..e04daf29 100644
--- a/src/jsc/jsc_class.hpp
+++ b/src/jsc/jsc_class.hpp
@@ -228,7 +228,7 @@ inline JSValueRef ObjectWrap<ClassType>::call(JSContextRef ctx, JSObjectRef func
     // Classes without a constructor should still be subclassable.
     if (reinterpret_cast<void*>(s_class.constructor)) {
         try {
-            s_class.constructor(ctx, this_object, argc, arguments);
+            s_class.constructor(ctx, function, this_object, argc, arguments);
         }
         catch (std::exception &e) {
             *exception = jsc::Exception::value(ctx, e);
@@ -248,7 +248,7 @@ inline JSObjectRef ObjectWrap<ClassType>::construct(JSContextRef ctx, JSObjectRe
 
     JSObjectRef this_object = create_instance(ctx);
     try {
-        s_class.constructor(ctx, this_object, argc, arguments);
+        s_class.constructor(ctx, constructor, this_object, argc, arguments);
     }
     catch (std::exception &e) {
         *exception = jsc::Exception::value(ctx, e);
diff --git a/src/node/node_class.hpp b/src/node/node_class.hpp
index 21cddad6..ea473c20 100644
--- a/src/node/node_class.hpp
+++ b/src/node/node_class.hpp
@@ -237,7 +237,7 @@ inline void ObjectWrap<ClassType>::construct(const v8::FunctionCallbackInfo<v8::
         wrap->Wrap(this_object);
 
         try {
-            s_class.constructor(isolate, this_object, arguments.size(), arguments.data());
+            s_class.constructor(isolate, info.Callee(), this_object, arguments.size(), arguments.data());
         }
         catch (std::exception &e) {
             Nan::ThrowError(node::Exception::value(isolate, e));