diff --git a/components/style/properties/longhand/inherited_svg.mako.rs b/components/style/properties/longhand/inherited_svg.mako.rs
index 937b9237911..5c2fee9a427 100644
--- a/components/style/properties/longhand/inherited_svg.mako.rs
+++ b/components/style/properties/longhand/inherited_svg.mako.rs
@@ -119,16 +119,19 @@ ${helpers.single_keyword("clip-rule", "nonzero evenodd",
 
 ${helpers.predefined_type("marker-start", "UrlOrNone", "Either::Second(None_)",
                           products="gecko",
+                          boxed = product == "gecko",
                           animatable="False",
                           spec="https://www.w3.org/TR/SVG2/painting.html#VertexMarkerProperties")}
 
 ${helpers.predefined_type("marker-mid", "UrlOrNone", "Either::Second(None_)",
                           products="gecko",
+                          boxed = product == "gecko",
                           animatable="False",
                           spec="https://www.w3.org/TR/SVG2/painting.html#VertexMarkerProperties")}
 
 ${helpers.predefined_type("marker-end", "UrlOrNone", "Either::Second(None_)",
                           products="gecko",
+                          boxed = product == "gecko",
                           animatable="False",
                           spec="https://www.w3.org/TR/SVG2/painting.html#VertexMarkerProperties")}
 
diff --git a/components/style/properties/longhand/list.mako.rs b/components/style/properties/longhand/list.mako.rs
index 81ce62a32e1..8049c06d05c 100644
--- a/components/style/properties/longhand/list.mako.rs
+++ b/components/style/properties/longhand/list.mako.rs
@@ -38,6 +38,7 @@ ${helpers.single_keyword("list-style-type", """
     spec="https://drafts.csswg.org/css-lists/#propdef-list-style-type")}
 
 ${helpers.predefined_type("list-style-image", "UrlOrNone", "Either::Second(None_)",
+                          boxed = product == "gecko",
                           initial_specified_value="Either::Second(None_)", animatable=False,
                           spec="https://drafts.csswg.org/css-lists/#propdef-list-style-image")}