diff --git a/dist/vis.js b/dist/vis.js
index c2328643..96fa5ca0 100644
--- a/dist/vis.js
+++ b/dist/vis.js
@@ -33432,6 +33432,7 @@ return /******/ (function(modules) { // webpackBootstrap
         var nodeIds = Object.keys(this.previousStates);
         var nodes = this.body.nodes;
         var velocities = this.physicsBody.velocities;
+        this.referenceState = {};
 
         for (var i = 0; i < nodeIds.length; i++) {
           var nodeId = nodeIds[i];
@@ -33465,7 +33466,7 @@ return /******/ (function(modules) { // webpackBootstrap
         var posThreshold = 0.3;
 
         for (var nodeId in this.referenceState) {
-          if (this.referenceState.hasOwnProperty(nodeId)) {
+          if (this.referenceState.hasOwnProperty(nodeId) && nodes[nodeId] !== undefined) {
             dx = nodes[nodeId].x - reference[nodeId].positions.x;
             dy = nodes[nodeId].y - reference[nodeId].positions.y;
 
diff --git a/lib/network/modules/PhysicsEngine.js b/lib/network/modules/PhysicsEngine.js
index 8b3e9184..c1a2c3fe 100644
--- a/lib/network/modules/PhysicsEngine.js
+++ b/lib/network/modules/PhysicsEngine.js
@@ -417,6 +417,7 @@ class PhysicsEngine {
     var nodeIds = Object.keys(this.previousStates);
     var nodes = this.body.nodes;
     var velocities = this.physicsBody.velocities;
+    this.referenceState = {};
 
     for (let i = 0; i < nodeIds.length; i++) {
       let nodeId = nodeIds[i];
@@ -447,7 +448,7 @@ class PhysicsEngine {
     let posThreshold = 0.3;
 
     for (let nodeId in this.referenceState) {
-      if (this.referenceState.hasOwnProperty(nodeId)) {
+      if (this.referenceState.hasOwnProperty(nodeId) && nodes[nodeId] !== undefined) {
         dx = nodes[nodeId].x - reference[nodeId].positions.x;
         dy = nodes[nodeId].y - reference[nodeId].positions.y;