diff --git a/servo/components/style/rule_tree/mod.rs b/servo/components/style/rule_tree/mod.rs
index 02c329257ace..e2a8cbc106e6 100644
--- a/servo/components/style/rule_tree/mod.rs
+++ b/servo/components/style/rule_tree/mod.rs
@@ -488,8 +488,6 @@ pub enum CascadeLevel {
     PresHints,
     /// User normal rules.
     UserNormal,
-    /// XBL <stylesheet> rules.
-    XBL,
     /// Author normal rules.
     AuthorNormal,
     /// Style attribute normal rules.
@@ -1258,7 +1256,6 @@ impl StrongRuleNode {
                     }
                     // Author rules:
                     CascadeLevel::PresHints |
-                    CascadeLevel::XBL |
                     CascadeLevel::AuthorNormal |
                     CascadeLevel::StyleAttributeNormal |
                     CascadeLevel::SMILOverride |
diff --git a/servo/components/style/stylist.rs b/servo/components/style/stylist.rs
index 038b7ceb8887..33a4000172f7 100644
--- a/servo/components/style/stylist.rs
+++ b/servo/components/style/stylist.rs
@@ -1309,7 +1309,7 @@ impl Stylist {
                     &mut matching_context,
                     stylist.quirks_mode,
                     flags_setter,
-                    CascadeLevel::XBL,
+                    CascadeLevel::AuthorNormal,
                 );
             }
         });