diff --git a/src/shapes/Shape.js b/src/shapes/Shape.js
index a90cfd4d..00bd9211 100644
--- a/src/shapes/Shape.js
+++ b/src/shapes/Shape.js
@@ -2,8 +2,8 @@ module.exports = Shape;
 
 var vec2 = require('../math/vec2');
 
-let PLAYER = Math.pow(2,0);
-let EVERYTHING_EXCEPT_PLAYER =  Math.pow(2,1);
+var PLAYER = Math.pow(2,0);
+var EVERYTHING_EXCEPT_PLAYER =  Math.pow(2,1);
 
 /**
  * Base class for shapes.
@@ -115,7 +115,7 @@ function Shape(options){
      * @type {Number}
      */
     this.collisionMask = options.collisionMask !== undefined ? options.collisionMask : EVERYTHING_EXCEPT_PLAYER | PLAYER;
- 
+
     /**
      * Material to use in collisions for this Shape. If this is set to null, the world will use default material properties instead.
      * @property material
@@ -244,4 +244,4 @@ Shape.prototype.computeAABB = function(out, position, angle){
  */
 Shape.prototype.raycast = function(result, ray, position, angle){
     // To be implemented in each subclass
-};
\ No newline at end of file
+};
diff --git a/src/world/IslandManager.js b/src/world/IslandManager.js
index bebfe712..6bcd5f9b 100644
--- a/src/world/IslandManager.js
+++ b/src/world/IslandManager.js
@@ -167,10 +167,14 @@ IslandManager.prototype.split = function(world){
             j=bodies.indexOf(eq.bodyB),
             ni=nodes[i],
             nj=nodes[j];
-        ni.neighbors.push(nj);
-        nj.neighbors.push(ni);
-        ni.equations.push(eq);
-        nj.equations.push(eq);
+        if (ni) {
+            ni.neighbors.push(nj);
+            ni.equations.push(eq);
+        }
+        if (nj) {
+            nj.neighbors.push(ni);
+            nj.equations.push(eq);
+        }
     }
 
     // Move old islands to the island pool