diff --git a/tests/ref/basic.list b/tests/ref/basic.list
index 8cb8d854f48..c3cdd1df6fa 100644
--- a/tests/ref/basic.list
+++ b/tests/ref/basic.list
@@ -12,7 +12,6 @@ fragment=top != ../html/acid2.html acid2_ref.html
== acid1_a.html acid1_b.html
== acid2_noscroll.html acid2_ref_broken.html
flaky_cpu == append_style_a.html append_style_b.html
-== basic_width_px.html basic_width_em.html
== block_formatting_context_a.html block_formatting_context_ref.html
== block_formatting_context_cleared_float_a.html block_formatting_context_cleared_float_ref.html
== block_formatting_context_complex_a.html block_formatting_context_complex_ref.html
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index f4b712f40e4..cca460351f1 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -423,6 +423,18 @@
"url": "/_mozilla/css/background_style_attr.html"
}
],
+ "css/basic_width_px.html": [
+ {
+ "path": "css/basic_width_px.html",
+ "references": [
+ [
+ "/_mozilla/css/basic_width_em.html",
+ "=="
+ ]
+ ],
+ "url": "/_mozilla/css/basic_width_px.html"
+ }
+ ],
"css/class-namespaces.html": [
{
"path": "css/class-namespaces.html",
@@ -1628,6 +1640,18 @@
"url": "/_mozilla/css/background_style_attr.html"
}
],
+ "css/basic_width_px.html": [
+ {
+ "path": "css/basic_width_px.html",
+ "references": [
+ [
+ "/_mozilla/css/basic_width_em.html",
+ "=="
+ ]
+ ],
+ "url": "/_mozilla/css/basic_width_px.html"
+ }
+ ],
"css/class-namespaces.html": [
{
"path": "css/class-namespaces.html",
diff --git a/tests/ref/basic_width_em.html b/tests/wpt/mozilla/tests/css/basic_width_em.html
similarity index 100%
rename from tests/ref/basic_width_em.html
rename to tests/wpt/mozilla/tests/css/basic_width_em.html
diff --git a/tests/ref/basic_width_px.html b/tests/wpt/mozilla/tests/css/basic_width_px.html
similarity index 83%
rename from tests/ref/basic_width_px.html
rename to tests/wpt/mozilla/tests/css/basic_width_px.html
index 660fa676246..a9b7e177019 100644
--- a/tests/ref/basic_width_px.html
+++ b/tests/wpt/mozilla/tests/css/basic_width_px.html
@@ -1,5 +1,6 @@
+