diff --git a/tests/ref/basic.list b/tests/ref/basic.list
index b44a7b24166..7dfd0fa5650 100644
--- a/tests/ref/basic.list
+++ b/tests/ref/basic.list
@@ -50,7 +50,6 @@ flaky_cpu == append_style_a.html append_style_b.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
== float_clearance_intrinsic_width_a.html float_clearance_intrinsic_width_ref.html
-== float_positioned_pseudo_stacking_context.html float_positioned_pseudo_stacking_context_ref.html
== floated_negative_margins_a.html floated_negative_margins_ref.html
== font_size.html font_size_ref.html
# `?` and `#` in the name is a test for https://github.com/servo/servo/issues/3340
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index e3355cfef71..a3509dadaad 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -863,6 +863,18 @@
"url": "/_mozilla/css/float_overflow_area_a.html"
}
],
+ "css/float_positioned_pseudo_stacking_context.html": [
+ {
+ "path": "css/float_positioned_pseudo_stacking_context.html",
+ "references": [
+ [
+ "/_mozilla/css/float_positioned_pseudo_stacking_context_ref.html",
+ "=="
+ ]
+ ],
+ "url": "/_mozilla/css/float_positioned_pseudo_stacking_context.html"
+ }
+ ],
"css/float_right_intrinsic_width_a.html": [
{
"path": "css/float_right_intrinsic_width_a.html",
@@ -5040,6 +5052,18 @@
"url": "/_mozilla/css/float_overflow_area_a.html"
}
],
+ "css/float_positioned_pseudo_stacking_context.html": [
+ {
+ "path": "css/float_positioned_pseudo_stacking_context.html",
+ "references": [
+ [
+ "/_mozilla/css/float_positioned_pseudo_stacking_context_ref.html",
+ "=="
+ ]
+ ],
+ "url": "/_mozilla/css/float_positioned_pseudo_stacking_context.html"
+ }
+ ],
"css/float_right_intrinsic_width_a.html": [
{
"path": "css/float_right_intrinsic_width_a.html",
diff --git a/tests/ref/float_positioned_pseudo_stacking_context.html b/tests/wpt/mozilla/tests/css/float_positioned_pseudo_stacking_context.html
similarity index 82%
rename from tests/ref/float_positioned_pseudo_stacking_context.html
rename to tests/wpt/mozilla/tests/css/float_positioned_pseudo_stacking_context.html
index 567608dee9a..9aae3ec767e 100644
--- a/tests/ref/float_positioned_pseudo_stacking_context.html
+++ b/tests/wpt/mozilla/tests/css/float_positioned_pseudo_stacking_context.html
@@ -1,4 +1,5 @@
+