diff --git a/src/Navigator.js b/src/Navigator.js
index 08f51df..b41bf96 100644
--- a/src/Navigator.js
+++ b/src/Navigator.js
@@ -1000,9 +1000,7 @@ var Navigator = createReactClass({
 
   _transitionSceneStyle: function(fromIndex, toIndex, progress, index) {
     var viewAtIndex = this._sceneRefs[index];
-    if (viewAtIndex === null || viewAtIndex === undefined) {
-      return;
-    }
+    if (!viewAtIndex) return;
     // Use toIndex animation when we move forwards. Use fromIndex when we move back
     var sceneConfigIndex = fromIndex < toIndex ? toIndex : fromIndex;
     var sceneConfig = this.state.sceneConfigStack[sceneConfigIndex];
@@ -1010,6 +1008,7 @@ var Navigator = createReactClass({
     if (!sceneConfig) {
       sceneConfig = this.state.sceneConfigStack[sceneConfigIndex - 1];
     }
+    if (!sceneConfig) return;
     var styleToUse = {};
     var useFn = index < fromIndex || index < toIndex ?
       sceneConfig.animationInterpolators.out :