diff --git a/css/css-typed-om/stylevalue-subclasses/numeric-objects/parse.tentative.html b/css/css-typed-om/stylevalue-subclasses/numeric-objects/parse.tentative.html
index 9b9f2f601ae5e79..382c81390369dd2 100644
--- a/css/css-typed-om/stylevalue-subclasses/numeric-objects/parse.tentative.html
+++ b/css/css-typed-om/stylevalue-subclasses/numeric-objects/parse.tentative.html
@@ -23,6 +23,10 @@
   assert_throws_dom("SyntaxError", () => CSSNumericValue.parse('calc(calc(1px * 2s) + 3%)'));
 }, 'Parsing a calc with incompatible units throws a SyntaxError');
 
+test(() => {
+  assert_throws_dom("SyntaxError", () => CSSNumericValue.parse('1xyz'));
+}, 'Parsing a <dimension-token> with invalid units throws a SyntaxError');
+
 test(() => {
   assert_style_value_equals(new CSSUnitValue(1, 'px'), CSSNumericValue.parse(' 1px  '));
 }, 'Parsing ignores surrounding spaces');