diff --git a/tests/unit/script/size_of.rs b/tests/unit/script/size_of.rs
index 7b385cdfee9..b89ca9dd837 100644
--- a/tests/unit/script/size_of.rs
+++ b/tests/unit/script/size_of.rs
@@ -39,9 +39,9 @@ macro_rules! sizeof_checker (
 // Update the sizes here
 sizeof_checker!(size_event_target, EventTarget, 40);
 sizeof_checker!(size_node, Node, 168);
-sizeof_checker!(size_element, Element, 304);
-sizeof_checker!(size_htmlelement, HTMLElement, 320);
-sizeof_checker!(size_div, HTMLDivElement, 320);
-sizeof_checker!(size_span, HTMLSpanElement, 320);
+sizeof_checker!(size_element, Element, 312);
+sizeof_checker!(size_htmlelement, HTMLElement, 328);
+sizeof_checker!(size_div, HTMLDivElement, 328);
+sizeof_checker!(size_span, HTMLSpanElement, 328);
 sizeof_checker!(size_text, Text, 200);
 sizeof_checker!(size_characterdata, CharacterData, 200);