diff --git a/_scss/components/_core.scss b/_scss/components/_core.scss
index ae17c9e..9e19359 100644
--- a/_scss/components/_core.scss
+++ b/_scss/components/_core.scss
@@ -1,11 +1,10 @@
-@import 'utilities/boxsizing';
 @import 'utilities/textsizeadjust';
 
 *,
 *::after,
 *::before {
-  @include box-sizing(border-box);
   @include text-size-adjust(100%);
+  box-sizing: border-box;
 }
 
 html {
diff --git a/_scss/utilities/_boxsizing.scss b/_scss/utilities/_boxsizing.scss
deleted file mode 100644
index 7e06a3e..0000000
--- a/_scss/utilities/_boxsizing.scss
+++ /dev/null
@@ -1,15 +0,0 @@
-// Box Sizing
-//
-// The box-sizing property in CSS controls how the box model
-// is handled for the element it applies to.
-//
-// Values: content-box | border-box
-// Default: content-box
-//
-// https://www.w3.org/TR/css-ui-3/#box-sizing
-@mixin box-sizing($value: content-box) {
-  -webkit-box-sizing: $value;
-     -moz-box-sizing: $value;
-      -ms-box-sizing: $value;
-          box-sizing: $value;
-}