diff --git a/scss/_reboot.scss b/scss/_reboot.scss
index acd1138bb6..bf0eb9e250 100644
--- a/scss/_reboot.scss
+++ b/scss/_reboot.scss
@@ -49,7 +49,7 @@
 body {
   margin: 0; // 1
   font-family: var(--#{$variable-prefix}body-font-family);
-  @include font-size(var(--#{$variable-prefix}body-font-size));
+  font-size: var(--#{$variable-prefix}body-font-size);
   font-weight: var(--#{$variable-prefix}body-font-weight);
   line-height: var(--#{$variable-prefix}body-line-height);
   color: var(--#{$variable-prefix}body-color);
diff --git a/scss/_root.scss b/scss/_root.scss
index 5e138e97b4..2927c343ff 100644
--- a/scss/_root.scss
+++ b/scss/_root.scss
@@ -41,7 +41,7 @@
     --#{$variable-prefix}root-font-size: #{$font-size-root};
   }
   --#{$variable-prefix}body-font-family: #{$font-family-base};
-  --#{$variable-prefix}body-font-size: #{$font-size-base};
+  @include rfs($font-size-base, --#{$variable-prefix}body-font-size);
   --#{$variable-prefix}body-font-weight: #{$font-weight-base};
   --#{$variable-prefix}body-line-height: #{$line-height-base};
   --#{$variable-prefix}body-color: #{$body-color};