diff --git a/components/style/gecko/wrapper.rs b/components/style/gecko/wrapper.rs
index 9ff92a19e16..a666d571ed9 100644
--- a/components/style/gecko/wrapper.rs
+++ b/components/style/gecko/wrapper.rs
@@ -181,7 +181,6 @@ impl<'lr> TShadowRoot for GeckoShadowRoot<'lr> {
 
         let author_styles = AuthorStyles::<GeckoStyleSheet>::from_ffi(author_styles);
 
-        debug_assert!(!author_styles.stylesheets.dirty());
         debug_assert!(
             author_styles.quirks_mode == self.as_node().owner_doc().quirks_mode() ||
                 author_styles.stylesheets.is_empty()