diff --git a/mozilla/layout/html/document/src/ua.css b/mozilla/layout/html/document/src/ua.css
index 1aa27cdc9b4..a81c756fc48 100644
--- a/mozilla/layout/html/document/src/ua.css
+++ b/mozilla/layout/html/document/src/ua.css
@@ -120,9 +120,6 @@ A:out-of-date IMG { border: 2px solid red; text-decoration: underline }
 
 HR {
   display: block;
-  height: 3px;
-  margin-top: 5px;
-  margin-bottom: 5px;
 }
 
 BR {
diff --git a/mozilla/layout/style/ua.css b/mozilla/layout/style/ua.css
index 1aa27cdc9b4..a81c756fc48 100644
--- a/mozilla/layout/style/ua.css
+++ b/mozilla/layout/style/ua.css
@@ -120,9 +120,6 @@ A:out-of-date IMG { border: 2px solid red; text-decoration: underline }
 
 HR {
   display: block;
-  height: 3px;
-  margin-top: 5px;
-  margin-bottom: 5px;
 }
 
 BR {