diff --git a/scss/grid-system/_reboot.scss b/scss/grid-system/_reboot.scss
index 372d59c..a6a5324 100644
--- a/scss/grid-system/_reboot.scss
+++ b/scss/grid-system/_reboot.scss
@@ -54,7 +54,7 @@
 
   // IE10+ doesn't honor `<meta name='viewport'>` in some cases.
   @at-root {
-    @include prefixer-selector(viewport, ms) {
+    @-ms-viewport {
       width: device-width;
     }
   }