diff --git a/tests/ref/basic.list b/tests/ref/basic.list
index fb2732db833..91a52866ef2 100644
--- a/tests/ref/basic.list
+++ b/tests/ref/basic.list
@@ -28,7 +28,6 @@ flaky_cpu == append_style_a.html append_style_b.html
== canvas_radial_gradient_a.html canvas_radial_gradient_ref.html
== case-insensitive-font-family.html case-insensitive-font-family-ref.html
== empty_cells_a.html empty_cells_ref.html
-== filter_opacity_a.html filter_opacity_ref.html
== fixed_width_overrides_child_intrinsic_width_a.html fixed_width_overrides_child_intrinsic_width_ref.html
prefs:"layout.flex-direction.enabled,layout.flex.enabled" == flex_column_direction.html flex_column_direction_ref.html
prefs:"layout.flex.enabled" == flex_row_direction.html flex_row_direction_ref.html
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index ec04f24c577..77ce3c95686 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -971,6 +971,18 @@
"url": "/_mozilla/css/filter_inline_a.html"
}
],
+ "css/filter_opacity_a.html": [
+ {
+ "path": "css/filter_opacity_a.html",
+ "references": [
+ [
+ "/_mozilla/css/filter_opacity_ref.html",
+ "=="
+ ]
+ ],
+ "url": "/_mozilla/css/filter_opacity_a.html"
+ }
+ ],
"css/filter_sepia_a.html": [
{
"path": "css/filter_sepia_a.html",
@@ -5376,6 +5388,18 @@
"url": "/_mozilla/css/filter_inline_a.html"
}
],
+ "css/filter_opacity_a.html": [
+ {
+ "path": "css/filter_opacity_a.html",
+ "references": [
+ [
+ "/_mozilla/css/filter_opacity_ref.html",
+ "=="
+ ]
+ ],
+ "url": "/_mozilla/css/filter_opacity_a.html"
+ }
+ ],
"css/filter_sepia_a.html": [
{
"path": "css/filter_sepia_a.html",
diff --git a/tests/ref/filter_opacity_a.html b/tests/wpt/mozilla/tests/css/filter_opacity_a.html
similarity index 75%
rename from tests/ref/filter_opacity_a.html
rename to tests/wpt/mozilla/tests/css/filter_opacity_a.html
index efd8de5bc82..6c488755628 100644
--- a/tests/ref/filter_opacity_a.html
+++ b/tests/wpt/mozilla/tests/css/filter_opacity_a.html
@@ -1,6 +1,7 @@
+