diff --git a/src/sass/plugins/ads.scss b/src/sass/plugins/ads.scss
index 5b109279f..8f5af141e 100644
--- a/src/sass/plugins/ads.scss
+++ b/src/sass/plugins/ads.scss
@@ -2,7 +2,7 @@
 // Advertisements
 // ==========================================================================
 
-@use 'sass:list';
+@use 'sass:math';
 
 .plyr__ads {
   border-radius: inherit;
@@ -49,7 +49,7 @@
   display: block;
   height: $plyr-range-track-height;
   left: 0;
-  margin: -(list.slash($plyr-range-track-height, 2)) 0 0;
+  margin: -calc($plyr-range-track-height / 2) 0 0;
   opacity: 0.8;
   position: absolute;
   top: 50%;