diff --git a/tests/ref/basic.list b/tests/ref/basic.list
index 52a0da584eb..f583f768bd9 100644
--- a/tests/ref/basic.list
+++ b/tests/ref/basic.list
@@ -112,7 +112,6 @@ prefs:"layout.writing-mode.enabled" == iframe/size_attributes_vertical_writing_m
== img_dynamic_remove.html img_dynamic_remove_ref.html
== img_padding_a.html img_padding_b.html
!= img_simple.html img_simple_ref.html
-== img_size_a.html img_size_b.html
== img_width_attribute_intrinsic_width_a.html img_width_attribute_intrinsic_width_ref.html
== img_width_style_intrinsic_width_a.html img_width_style_intrinsic_width_ref.html
== incremental_float_a.html incremental_float_ref.html
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index 9fd62a89099..0ddefdb5f94 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/img_size_a.html": [
+ {
+ "path": "css/img_size_a.html",
+ "references": [
+ [
+ "/_mozilla/css/img_size_b.html",
+ "=="
+ ]
+ ],
+ "url": "/_mozilla/css/img_size_a.html"
+ }
+ ],
"css/inline_block_border_a.html": [
{
"path": "css/inline_block_border_a.html",
@@ -4272,6 +4284,18 @@
"url": "/_mozilla/css/flex_nochild.html"
}
],
+ "css/img_size_a.html": [
+ {
+ "path": "css/img_size_a.html",
+ "references": [
+ [
+ "/_mozilla/css/img_size_b.html",
+ "=="
+ ]
+ ],
+ "url": "/_mozilla/css/img_size_a.html"
+ }
+ ],
"css/inline_block_border_a.html": [
{
"path": "css/inline_block_border_a.html",
diff --git a/tests/ref/img_size_a.html b/tests/wpt/mozilla/tests/css/img_size_a.html
similarity index 89%
rename from tests/ref/img_size_a.html
rename to tests/wpt/mozilla/tests/css/img_size_a.html
index a96abad3736..b6cedb2e1e1 100644
--- a/tests/ref/img_size_a.html
+++ b/tests/wpt/mozilla/tests/css/img_size_a.html
@@ -1,5 +1,6 @@
+
The winter is too cold for me...
diff --git a/tests/ref/img_size_b.html b/tests/wpt/mozilla/tests/css/img_size_b.html
similarity index 100%
rename from tests/ref/img_size_b.html
rename to tests/wpt/mozilla/tests/css/img_size_b.html