diff --git a/components/style/properties/longhands/box.mako.rs b/components/style/properties/longhands/box.mako.rs
index b6720eb564b..f5f09f32e6e 100644
--- a/components/style/properties/longhands/box.mako.rs
+++ b/components/style/properties/longhands/box.mako.rs
@@ -494,6 +494,7 @@ ${helpers.single_keyword(
     engines="gecko",
     spec="https://drafts.fxtf.org/compositing/#isolation",
     flags="CREATES_STACKING_CONTEXT",
+    gecko_enum_prefix="StyleIsolation",
     animation_value_type="discrete",
 )}