diff --git a/direct/src/distributed/DistributedSmoothNodeBase.py b/direct/src/distributed/DistributedSmoothNodeBase.py
index 6655e7de87..461587037a 100755
--- a/direct/src/distributed/DistributedSmoothNodeBase.py
+++ b/direct/src/distributed/DistributedSmoothNodeBase.py
@@ -200,6 +200,7 @@ class DistributedSmoothNodeBase:
 
     def d_broadcastPosHpr_XYH(self):
         # send out the minimal bits to describe our new position
+        assert not self.isEmpty(), 'DistributedSmoothNode %s has been removed from graph?' % self.doId
         xyz = self.getPos()
         h   = self.getH()