diff --git a/tests/ref/basic.list b/tests/ref/basic.list
index 84c99bbeb0f..3be3072676c 100644
--- a/tests/ref/basic.list
+++ b/tests/ref/basic.list
@@ -219,7 +219,6 @@ flaky_cpu == linebreak_simple_a.html linebreak_simple_b.html
== opacity_simple_a.html opacity_simple_ref.html
== opacity_stacking_context_a.html opacity_stacking_context_ref.html
== outline_offset_a.html outline_offset_ref.html
-== outlines_simple_a.html outlines_simple_ref.html
!= outset_blackborder.html blackborder_ref.html
# Should be == with expected failure. See #2797
!= overconstrained_block.html overconstrained_block_ref.html
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index 02650d29874..29d1b1b696f 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -683,6 +683,18 @@
"url": "/_mozilla/css/flex_nochild.html"
}
],
+ "css/outlines_simple_a.html": [
+ {
+ "path": "css/outlines_simple_a.html",
+ "references": [
+ [
+ "/_mozilla/css/outlines_simple_ref.html",
+ "=="
+ ]
+ ],
+ "url": "/_mozilla/css/outlines_simple_a.html"
+ }
+ ],
"css/outlines_wrap_a.html": [
{
"path": "css/outlines_wrap_a.html",
@@ -3432,6 +3444,18 @@
"url": "/_mozilla/css/flex_nochild.html"
}
],
+ "css/outlines_simple_a.html": [
+ {
+ "path": "css/outlines_simple_a.html",
+ "references": [
+ [
+ "/_mozilla/css/outlines_simple_ref.html",
+ "=="
+ ]
+ ],
+ "url": "/_mozilla/css/outlines_simple_a.html"
+ }
+ ],
"css/outlines_wrap_a.html": [
{
"path": "css/outlines_wrap_a.html",
diff --git a/tests/ref/outlines_simple_a.html b/tests/wpt/mozilla/tests/css/outlines_simple_a.html
similarity index 84%
rename from tests/ref/outlines_simple_a.html
rename to tests/wpt/mozilla/tests/css/outlines_simple_a.html
index 2dfc2e9a632..983df12c89b 100644
--- a/tests/ref/outlines_simple_a.html
+++ b/tests/wpt/mozilla/tests/css/outlines_simple_a.html
@@ -1,5 +1,6 @@
+