diff --git a/scene/register_scene_types.cpp b/scene/register_scene_types.cpp
index ddbb1a1afd..de00033a3b 100644
--- a/scene/register_scene_types.cpp
+++ b/scene/register_scene_types.cpp
@@ -526,6 +526,7 @@ void register_scene_types() {
 	ClassDB::register_class<QuadMesh>();
 	ClassDB::register_virtual_class<Material>();
 	ClassDB::register_class<SpatialMaterial>();
+	ClassDB::add_compatibility_class("FixedSpatialMaterial", "SpatialMaterial");
 	SceneTree::add_idle_callback(SpatialMaterial::flush_changes);
 	SpatialMaterial::init_shaders();