diff --git a/components/style/values/specified/box.rs b/components/style/values/specified/box.rs
index 584f594fb72..c100f0b446f 100644
--- a/components/style/values/specified/box.rs
+++ b/components/style/values/specified/box.rs
@@ -2207,7 +2207,10 @@ impl Parse for Overflow {
             "clip" => Self::Clip,
             #[cfg(feature = "gecko")]
             "-moz-hidden-unscrollable" if static_prefs::pref!("layout.css.overflow-moz-hidden-unscrollable.enabled") => {
-               Overflow::Clip
+                Overflow::Clip
+            },
+            "overlay" if static_prefs::pref!("layout.css.overflow-overlay.enabled") => {
+                Overflow::Auto
             },
         })
     }