diff --git a/examples/webgl_multiple_scenes_comparison.html b/examples/webgl_multiple_scenes_comparison.html
index 915be1c202f3435c08e8d3958922df4696bc483e..f1a5aeb04b8e239c50c31c5d09387787964ef8c1 100644
--- a/examples/webgl_multiple_scenes_comparison.html
+++ b/examples/webgl_multiple_scenes_comparison.html
@@ -163,7 +163,7 @@
 
 					sliderMoved = true;
 
-					sliderPos = e.pageX || e.touches[ 0 ].pageX;
+					sliderPos = ( e.pageX === undefined ) ? e.touches[ 0 ].pageX : e.pageX;
 
 					//prevent the slider from being positioned outside the window bounds
 					if ( sliderPos < 0 ) sliderPos = 0;