diff --git a/normalize.css b/normalize.css
index 192eb9ce4..2c7f6c6de 100644
--- a/normalize.css
+++ b/normalize.css
@@ -46,14 +46,11 @@ h1 {
    ========================================================================== */
 
 /**
- * 1. Add the correct box sizing in Firefox.
- * 2. Show the overflow in Edge and IE.
+ * 1. Show the overflow in Edge and IE.
  */
 
 hr {
-  box-sizing: content-box; /* 1 */
-  height: 0; /* 1 */
-  overflow: visible; /* 2 */
+  overflow: visible; /* 1 */
 }
 
 /**