diff --git a/test/css/media.css b/test/css/media.css
index eba937ca..5aa1d4e8 100644
--- a/test/css/media.css
+++ b/test/css/media.css
@@ -169,7 +169,7 @@
     }
   }
 }
-@media (-webkit-min-device-pixel-ratio: 2), (min--moz-device-pixel-ratio: 2), (-o-min-device-pixel-ratio: 2 / 1), (min-resolution: 2dppx), (min-resolution: 128dpcm) {
+@media (-webkit-min-device-pixel-ratio: 2), (min--moz-device-pixel-ratio: 2), (-o-min-device-pixel-ratio: 2/1), (min-resolution: 2dppx), (min-resolution: 128dpcm) {
   .b {
     background: red;
   }
diff --git a/test/less/media.less b/test/less/media.less
index 1e81c330..3d55d31d 100644
--- a/test/less/media.less
+++ b/test/less/media.less
@@ -20,7 +20,10 @@
     body { max-width: (@base * 60); }
 }
 
-@media all and (device-aspect-ratio: 16 / 9) {
+@ratio_large: 16;
+@ratio_small: 9;
+
+@media all and (device-aspect-ratio: @ratio_large / @ratio_small) {
    body { max-width: 800px; }
 }
 
@@ -172,7 +175,7 @@ body {
   }
 }
 
-@media (-webkit-min-device-pixel-ratio: 2), (min--moz-device-pixel-ratio: 2), (-o-min-device-pixel-ratio: 2 / 1), (min-resolution: 2dppx), (min-resolution: 128dpcm) {
+@media (-webkit-min-device-pixel-ratio: 2), (min--moz-device-pixel-ratio: 2), (-o-min-device-pixel-ratio: 2/1), (min-resolution: 2dppx), (min-resolution: 128dpcm) {
   .b {
     background: red;
   }