diff --git a/tests/ref/basic.list b/tests/ref/basic.list
index be7565f0b49..12c5a75247f 100644
--- a/tests/ref/basic.list
+++ b/tests/ref/basic.list
@@ -153,7 +153,6 @@ prefs:"layout.writing-mode.enabled" == iframe/size_attributes_vertical_writing_m
!= linear_gradients_corners_a.html linear_gradients_corners_ref.html
== linear_gradients_reverse_a.html linear_gradients_reverse_ref.html
!= linear_gradients_smoke_a.html linear_gradients_smoke_ref.html
-== linebreak_inline_span_a.html linebreak_inline_span_b.html
flaky_cpu == linebreak_simple_a.html linebreak_simple_b.html
# Fails intermittently (#3636)
# == link_style_dynamic_addition.html link_style_dynamic_addition_ref.html
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index c5db23b1d57..8a962fe6086 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -983,6 +983,18 @@
"url": "/_mozilla/css/linear_gradients_parsing_a.html"
}
],
+ "css/linebreak_inline_span_a.html": [
+ {
+ "path": "css/linebreak_inline_span_a.html",
+ "references": [
+ [
+ "/_mozilla/css/linebreak_inline_span_b.html",
+ "=="
+ ]
+ ],
+ "url": "/_mozilla/css/linebreak_inline_span_a.html"
+ }
+ ],
"css/max_width_float_simple_a.html": [
{
"path": "css/max_width_float_simple_a.html",
@@ -4392,6 +4404,18 @@
"url": "/_mozilla/css/linear_gradients_parsing_a.html"
}
],
+ "css/linebreak_inline_span_a.html": [
+ {
+ "path": "css/linebreak_inline_span_a.html",
+ "references": [
+ [
+ "/_mozilla/css/linebreak_inline_span_b.html",
+ "=="
+ ]
+ ],
+ "url": "/_mozilla/css/linebreak_inline_span_a.html"
+ }
+ ],
"css/max_width_float_simple_a.html": [
{
"path": "css/max_width_float_simple_a.html",
diff --git a/tests/ref/linebreak_inline_span_a.html b/tests/wpt/mozilla/tests/css/linebreak_inline_span_a.html
similarity index 92%
rename from tests/ref/linebreak_inline_span_a.html
rename to tests/wpt/mozilla/tests/css/linebreak_inline_span_a.html
index ddaeabcb653..dc1fd42f49d 100644
--- a/tests/ref/linebreak_inline_span_a.html
+++ b/tests/wpt/mozilla/tests/css/linebreak_inline_span_a.html
@@ -1,5 +1,6 @@
+