diff --git a/responsiveslides.js b/responsiveslides.js
index 1e6f465..9dee25d 100644
--- a/responsiveslides.js
+++ b/responsiveslides.js
@@ -343,7 +343,7 @@
 
             // Determine where to slide
             var idx = $slide.index($visibleClass),
-              prevIdx = idx - 1,
+              prevIdx = idx - 1 >= 0     ? index - 1 : length -1,
               nextIdx = idx + 1 < length ? index + 1 : 0;
 
             // Go to slide