diff --git a/css/css-transforms/transform-with-sign-function.html b/css/css-transforms/transform-with-sign-function.html
index 9f6b6f676c1a0d..40837e1ea63c17 100644
--- a/css/css-transforms/transform-with-sign-function.html
+++ b/css/css-transforms/transform-with-sign-function.html
@@ -15,5 +15,6 @@
 test_math_used('skew(calc(sign(1em - 1px) * 2deg), calc(sign(1em - 1px) * 2deg))', 'skew(2deg, 2deg)', {prop:'transform'});
 test_math_used('skewX(calc(sign(1em - 1px) * 2deg))', 'skewX(2deg)', {prop:'transform'});
 test_math_used('skewY(calc(sign(1em - 1px) * 2deg))', 'skewY(2deg)', {prop:'transform'});
+test_math_used('matrix(calc(sign(1em - 1px) * 2), calc(sign(1em - 1px) * 2), calc(sign(1em - 1px) * 2), calc(sign(1em - 1px) * 2), calc(sign(1em - 1px) * 2), calc(sign(1em - 1px) * 2))', 'matrix(2, 2, 2, 2, 2, 2)', {prop:'transform'});
 
 </script>