diff --git a/tests/ref/basic.list b/tests/ref/basic.list
index 3ab37363b88..21ed4be1575 100644
--- a/tests/ref/basic.list
+++ b/tests/ref/basic.list
@@ -38,7 +38,6 @@ prefs:"layout.writing-mode.enabled" == iframe/size_attributes_vertical_writing_m
flaky_cpu == linebreak_simple_a.html linebreak_simple_b.html
# Fails intermittently (#3636)
# == link_style_dynamic_addition.html link_style_dynamic_addition_ref.html
-!= noteq_attr_exists_selector.html attr_exists_selector_ref.html
!= octicons_a.html octicons_ref.html
== ol_japanese_iroha_a.html ol_japanese_iroha_ref.html
!= ol_japanese_iroha_bullet_styles.html ol_japanese_iroha_ref.html
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index 7fb977985eb..08f559d03ca 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -206,6 +206,10 @@
[
"/_mozilla/css/attr_exists_selector_ref.html",
"=="
+ ],
+ [
+ "/_mozilla/css/noteq_attr_exists_selector.html",
+ "!="
]
],
"url": "/_mozilla/css/attr_exists_selector.html"
@@ -5463,6 +5467,10 @@
[
"/_mozilla/css/attr_exists_selector_ref.html",
"=="
+ ],
+ [
+ "/_mozilla/css/noteq_attr_exists_selector.html",
+ "!="
]
],
"url": "/_mozilla/css/attr_exists_selector.html"
diff --git a/tests/wpt/mozilla/tests/css/attr_exists_selector.html b/tests/wpt/mozilla/tests/css/attr_exists_selector.html
index a40f01e361d..9290ff83863 100644
--- a/tests/wpt/mozilla/tests/css/attr_exists_selector.html
+++ b/tests/wpt/mozilla/tests/css/attr_exists_selector.html
@@ -3,6 +3,7 @@
Attribute exists selector: [foo] and [*|foo]
+