diff --git a/src/navigator.js b/src/navigator.js
index bb4e08d6..4b2018fb 100644
--- a/src/navigator.js
+++ b/src/navigator.js
@@ -284,7 +284,7 @@ $.extend( $.Navigator.prototype, $.EventSource.prototype, $.Viewer.prototype, /*
     setFlip: function(state) {
       this.viewport.setFlip(state);
 
-      var flip = ((this.viewport.getFlip() && !this.viewer.world._items[0].getFlip()) || (!this.viewport.getFlip() && this.viewer.world._items[0].getFlip()));
+      var flip = ((this.viewport.getFlip() && this.viewer.world._items[0] && !this.viewer.world._items[0].getFlip()) || (!this.viewport.getFlip() && this.viewer.world._items[0] && this.viewer.world._items[0].getFlip()));
       this.setDisplayTransform(flip ? "scale(-1,1)" : "scale(1,1)");
       return this;
     },
diff --git a/src/viewer.js b/src/viewer.js
index f622829c..ac3701b4 100644
--- a/src/viewer.js
+++ b/src/viewer.js
@@ -3367,7 +3367,7 @@ function updateOnce( viewer ) {
     THIS[ viewer.hash ].animating = animated;
 
     // Update navigator flip transformation
-    if (viewer.navigator && viewer.viewport != "undefined"){
+    if (viewer.navigator && viewer.viewport != undefined){
       viewer.navigator.setFlip(viewer.viewport.getFlip());
     }
     //viewer.profiler.endUpdate();