diff --git a/tests/ref/basic.list b/tests/ref/basic.list
index 4d441069697..3ab37363b88 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
-== marker_block_direction_placement_a.html marker_block_direction_placement_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
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index 01587c3fda4..7fb977985eb 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -2595,6 +2595,18 @@
"url": "/_mozilla/css/margins_inside_floats_a.html"
}
],
+ "css/marker_block_direction_placement_a.html": [
+ {
+ "path": "css/marker_block_direction_placement_a.html",
+ "references": [
+ [
+ "/_mozilla/css/marker_block_direction_placement_ref.html",
+ "=="
+ ]
+ ],
+ "url": "/_mozilla/css/marker_block_direction_placement_a.html"
+ }
+ ],
"css/max_width_float_simple_a.html": [
{
"path": "css/max_width_float_simple_a.html",
@@ -7840,6 +7852,18 @@
"url": "/_mozilla/css/margins_inside_floats_a.html"
}
],
+ "css/marker_block_direction_placement_a.html": [
+ {
+ "path": "css/marker_block_direction_placement_a.html",
+ "references": [
+ [
+ "/_mozilla/css/marker_block_direction_placement_ref.html",
+ "=="
+ ]
+ ],
+ "url": "/_mozilla/css/marker_block_direction_placement_a.html"
+ }
+ ],
"css/max_width_float_simple_a.html": [
{
"path": "css/max_width_float_simple_a.html",
diff --git a/tests/ref/marker_block_direction_placement_a.html b/tests/wpt/mozilla/tests/css/marker_block_direction_placement_a.html
similarity index 67%
rename from tests/ref/marker_block_direction_placement_a.html
rename to tests/wpt/mozilla/tests/css/marker_block_direction_placement_a.html
index a5e884245fb..53fd30e113e 100644
--- a/tests/ref/marker_block_direction_placement_a.html
+++ b/tests/wpt/mozilla/tests/css/marker_block_direction_placement_a.html
@@ -1,4 +1,5 @@
+