diff --git a/mozilla/layout/html/document/src/ua.css b/mozilla/layout/html/document/src/ua.css
index 50f78cb8d1f..6e77635a133 100644
--- a/mozilla/layout/html/document/src/ua.css
+++ b/mozilla/layout/html/document/src/ua.css
@@ -237,6 +237,9 @@ TH {
 CAPTION {
   text-align: center;
 }
+MULTICOL {
+  display: block;
+}
 
 // XXX Special rule to eliminate margin around for nav4 compatability
 // XXX This isn't good enough because we only want the margin eliminated
diff --git a/mozilla/layout/style/ua.css b/mozilla/layout/style/ua.css
index 50f78cb8d1f..6e77635a133 100644
--- a/mozilla/layout/style/ua.css
+++ b/mozilla/layout/style/ua.css
@@ -237,6 +237,9 @@ TH {
 CAPTION {
   text-align: center;
 }
+MULTICOL {
+  display: block;
+}
 
 // XXX Special rule to eliminate margin around for nav4 compatability
 // XXX This isn't good enough because we only want the margin eliminated