diff --git a/demos/2d/rubegoldberg/engine.cfg b/demos/2d/rubegoldberg/engine.cfg
index f0c306a53da..bd1cc79ddba 100644
--- a/demos/2d/rubegoldberg/engine.cfg
+++ b/demos/2d/rubegoldberg/engine.cfg
@@ -6,6 +6,5 @@ icon="res://icon.png"
 
 [physics_2d]
 
-thread_model=2
 default_gravity=500
 default_density=0.01