--- a/layout/style/test/stylo-failures.md
+++ b/layout/style/test/stylo-failures.md
@@ -192,17 +192,16 @@ to mochitest command.
   * -moz-alt-content parsing is wrong: servo/servo#15726
     * test_property_syntax_errors.html `-moz-alt-content` [4]
   * mask shorthand servo/servo#15772
     * test_property_syntax_errors.html `mask'` [76]
 * Incorrect serialization
   * border-radius and -moz-outline-radius shorthand servo/servo#15169
   * color value not canonicalized servo/servo#15397
     * test_shorthand_property_getters.html `should condense to canonical case` [2]
-  * test_variables.html `--weird`: name of custom property is not escaped properly servo/servo#15399 [1]
   * :not(*) doesn't serialize properly servo/servo#16017
     * test_selectors.html `:not()` [8]
     * ... `:not(html|)` [1]
   * "*|a" gets serialized as "a" when it should not servo/servo#16020
     * test_selectors.html `reserialization of *|a` [6]
 * Unsupported pseudo-elements or anon boxes
   * :-moz-tree bits bug 1348488
     * test_selectors.html `:-moz-tree` [10]