diff --git a/js/reveal.js b/js/reveal.js
index 5805ee9..9634c6b 100644
--- a/js/reveal.js
+++ b/js/reveal.js
@@ -1446,6 +1446,7 @@
 			var size = getComputedSlideSize();
 
 			var slidePadding = 20; // TODO Dig this out of DOM
+			var zTransform = z !== 0 ? 'translateZ(-'+ z +'px)' : '';
 
 			// Layout the contents of the slides
 			layoutSlideContents( config.width, config.height, slidePadding );
@@ -1467,13 +1468,13 @@
 				dom.slides.style.top = '';
 				dom.slides.style.bottom = '';
 				dom.slides.style.right = '';
-				transformElement( dom.slides, '' );
+				transformElement( dom.slides, zTransform );
 			}
 			else {
 				// Prefer zooming in desktop Chrome so that content remains crisp
 				if( !isMobileDevice && /chrome/i.test( navigator.userAgent ) && typeof dom.slides.style.zoom !== 'undefined' ) {
 					dom.slides.style.zoom = scale;
-					transformElement( dom.slides, 'translateZ(-'+ z +'px)' );
+					transformElement( dom.slides, zTransform );
 				}
 				// Apply scale transform as a fallback
 				else {
@@ -1481,7 +1482,7 @@
 					dom.slides.style.top = '50%';
 					dom.slides.style.bottom = 'auto';
 					dom.slides.style.right = 'auto';
-					transformElement( dom.slides, 'translate(-50%, -50%) scale('+ scale +')' + ' translateZ(-'+ z +'px)' );
+					transformElement( dom.slides, 'translate(-50%, -50%) scale('+ scale +') ' + zTransform );
 				}
 			}