diff --git a/core/resource.cpp b/core/resource.cpp
index 987bd772b0f..560ca9a1f2f 100644
--- a/core/resource.cpp
+++ b/core/resource.cpp
@@ -130,7 +130,7 @@ void ResourceImportMetadata::_bind_methods() {
 
 	ObjectTypeDB::bind_method(_MD("set_editor","name"),&ResourceImportMetadata::set_editor);
 	ObjectTypeDB::bind_method(_MD("get_editor"),&ResourceImportMetadata::get_editor);
-	ObjectTypeDB::bind_method(_MD("add_source","path","md5"),&ResourceImportMetadata::add_source);
+	ObjectTypeDB::bind_method(_MD("add_source","path","md5"),&ResourceImportMetadata::add_source, "");
 	ObjectTypeDB::bind_method(_MD("get_source_path","idx"),&ResourceImportMetadata::get_source_path);
 	ObjectTypeDB::bind_method(_MD("get_source_md5","idx"),&ResourceImportMetadata::get_source_md5);
 	ObjectTypeDB::bind_method(_MD("remove_source","idx"),&ResourceImportMetadata::remove_source);