diff --git a/tests/ref/basic.list b/tests/ref/basic.list
index 173090cad6a..73cce617306 100644
--- a/tests/ref/basic.list
+++ b/tests/ref/basic.list
@@ -115,7 +115,6 @@ prefs:"layout.writing-mode.enabled" == iframe/size_attributes_vertical_writing_m
== 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_inline_layout_a.html incremental_inline_layout_ref.html
-== incremental_letter_spacing_a.html incremental_letter_spacing_ref.html
== incremental_text_color_a.html incremental_text_color_ref.html
!= inline_background_a.html inline_background_ref.html
== inline_block_baseline_a.html inline_block_baseline_ref.html
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index 26ec84e1c3e..fb556642b5b 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -707,6 +707,18 @@
"url": "/_mozilla/css/incremental_float_a.html"
}
],
+ "css/incremental_letter_spacing_a.html": [
+ {
+ "path": "css/incremental_letter_spacing_a.html",
+ "references": [
+ [
+ "/_mozilla/css/incremental_letter_spacing_ref.html",
+ "=="
+ ]
+ ],
+ "url": "/_mozilla/css/incremental_letter_spacing_a.html"
+ }
+ ],
"css/inline_absolute_hypothetical_clip_a.html": [
{
"path": "css/inline_absolute_hypothetical_clip_a.html",
@@ -4380,6 +4392,18 @@
"url": "/_mozilla/css/incremental_float_a.html"
}
],
+ "css/incremental_letter_spacing_a.html": [
+ {
+ "path": "css/incremental_letter_spacing_a.html",
+ "references": [
+ [
+ "/_mozilla/css/incremental_letter_spacing_ref.html",
+ "=="
+ ]
+ ],
+ "url": "/_mozilla/css/incremental_letter_spacing_a.html"
+ }
+ ],
"css/inline_absolute_hypothetical_clip_a.html": [
{
"path": "css/inline_absolute_hypothetical_clip_a.html",
diff --git a/tests/ref/incremental_letter_spacing_a.html b/tests/wpt/mozilla/tests/css/incremental_letter_spacing_a.html
similarity index 83%
rename from tests/ref/incremental_letter_spacing_a.html
rename to tests/wpt/mozilla/tests/css/incremental_letter_spacing_a.html
index 351cd100d05..1a41febe450 100644
--- a/tests/ref/incremental_letter_spacing_a.html
+++ b/tests/wpt/mozilla/tests/css/incremental_letter_spacing_a.html
@@ -1,6 +1,7 @@
+
Incremental layout letter-spacing test
diff --git a/tests/ref/incremental_letter_spacing_ref.html b/tests/wpt/mozilla/tests/css/incremental_letter_spacing_ref.html
similarity index 100%
rename from tests/ref/incremental_letter_spacing_ref.html
rename to tests/wpt/mozilla/tests/css/incremental_letter_spacing_ref.html