diff --git a/CubeFlip/RSCubeView.m b/CubeFlip/RSCubeView.m
index b6a7078..8333845 100644
--- a/CubeFlip/RSCubeView.m
+++ b/CubeFlip/RSCubeView.m
@@ -292,7 +292,10 @@ - (void)animationDidStart:(CAAnimation *)animation {
 
 - (void)animationDidStop:(CAAnimation *)animation finished:(BOOL)finished {
 	
-	isAnimating = NO;
+	if (!isAnimating)
+        return;
+    
+    isAnimating = NO;
     self.contentView = nextView;
     
     [animationLayer removeFromSuperlayer];