diff --git a/js/reveal.js b/js/reveal.js
index b8026c1..626ce7a 100644
--- a/js/reveal.js
+++ b/js/reveal.js
@@ -2480,7 +2480,7 @@
 		// Solves an edge case where the previous slide maintains the
 		// 'present' class when navigating between adjacent vertical
 		// stacks
-		if( previousSlide ) {
+		if( previousSlide && previousSlide !== currentSlide ) {
 			previousSlide.classList.remove( 'present' );
 			previousSlide.setAttribute( 'aria-hidden', 'true' );