diff --git a/lib/size-lg.css b/lib/size-lg.css
index 661abd6..ffba3ae 100644
--- a/lib/size-lg.css
+++ b/lib/size-lg.css
@@ -193,8 +193,6 @@
    */
 
   .u-lg-sizeFull {
-    box-sizing: border-box !important;
-    display: block !important;
     width: 100% !important;
   }
 
diff --git a/lib/size-md.css b/lib/size-md.css
index cd3b6f2..392ee85 100644
--- a/lib/size-md.css
+++ b/lib/size-md.css
@@ -195,8 +195,6 @@
    */
 
   .u-md-sizeFull {
-    box-sizing: border-box !important;
-    display: block !important;
     width: 100% !important;
   }
 
diff --git a/lib/size-sm.css b/lib/size-sm.css
index a8a802a..dd8850c 100644
--- a/lib/size-sm.css
+++ b/lib/size-sm.css
@@ -193,8 +193,6 @@
    */
 
   .u-sm-sizeFull {
-    box-sizing: border-box !important;
-    display: block !important;
     width: 100% !important;
   }
 
diff --git a/lib/size.css b/lib/size.css
index b74e589..0de2425 100644
--- a/lib/size.css
+++ b/lib/size.css
@@ -191,7 +191,5 @@
  */
 
 .u-sizeFull {
-  box-sizing: border-box !important;
-  display: block !important;
   width: 100% !important;
 }
diff --git a/test/index.html b/test/index.html
index 32b44fa..6a70f23 100644
--- a/test/index.html
+++ b/test/index.html
@@ -9,6 +9,10 @@
     margin: 0 0 10px;
   }
 
+  html {
+    box-sizing: border-box;
+  }
+
   .u-flex {
     display: -webkit-flex !important;
     display: -ms-flexbox !important;