diff --git a/components/style/properties/longhands/svg.mako.rs b/components/style/properties/longhands/svg.mako.rs
index f25cbb8e019..724c38b2d1b 100644
--- a/components/style/properties/longhands/svg.mako.rs
+++ b/components/style/properties/longhands/svg.mako.rs
@@ -69,6 +69,7 @@ ${helpers.single_keyword(
     "mask-type",
     "luminance alpha",
     engines="gecko",
+    gecko_enum_prefix="StyleMaskType",
     animation_value_type="discrete",
     spec="https://drafts.fxtf.org/css-masking/#propdef-mask-type",
 )}