diff --git a/components/layout_2020/display_list/mod.rs b/components/layout_2020/display_list/mod.rs
index ba66a24a841..2e1af55c9db 100644
--- a/components/layout_2020/display_list/mod.rs
+++ b/components/layout_2020/display_list/mod.rs
@@ -14,8 +14,10 @@ use mitochondria::OnceCell;
 use net_traits::image_cache::UsePlaceholder;
 use std::sync::Arc;
 use style::computed_values::overflow_x::T as ComputedOverflow;
+use style::computed_values::position::T as ComputedPosition;
 use style::dom::OpaqueNode;
 use style::properties::ComputedValues;
+
 use style::values::computed::{BorderStyle, Length, LengthPercentage};
 use style::values::specified::ui::CursorKind;
 use webrender_api::{self as wr, units};
@@ -245,6 +247,7 @@ impl<'a> BuilderForBoxFragment<'a> {
 
     fn build(&mut self, builder: &mut DisplayListBuilder) {
         builder.clipping_and_scrolling_scope(|builder| {
+            self.adjust_spatial_id_for_positioning(builder);
             self.build_hit_test(builder);
             self.build_background(builder);
             self.build_border(builder);
@@ -264,6 +267,18 @@ impl<'a> BuilderForBoxFragment<'a> {
         });
     }
 
+    fn adjust_spatial_id_for_positioning(&self, builder: &mut DisplayListBuilder) {
+        if self.fragment.style.get_box().position != ComputedPosition::Fixed {
+            return;
+        }
+
+        // TODO(mrobinson): Eventually this should use the spatial id of the reference
+        // frame that is the parent of this one once we have full support for stacking
+        // contexts and transforms.
+        builder.current_space_and_clip.spatial_id =
+            wr::SpatialId::root_reference_frame(builder.wr.pipeline_id);
+    }
+
     fn build_scroll_frame_if_necessary(&self, builder: &mut DisplayListBuilder) {
         let overflow_x = self.fragment.style.get_box().overflow_x;
         let overflow_y = self.fragment.style.get_box().overflow_y;
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index 145f8189f02..c71d57cb722 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -1,5 +1,14 @@
 {
  "items": {
+  "conformancechecker": {
+   "css/position_fixed_scroll.html": []
+  },
+  "crashtest": {
+   "css/position_fixed_scroll.html": []
+  },
+  "manual": {
+   "css/position_fixed_scroll.html": []
+  },
   "reftest": {
    "css/abs-overflow-stackingcontext.html": [
     [
@@ -5057,6 +5066,18 @@
      {}
     ]
    ],
+   "css/position_fixed_scroll.html": [
+    [
+     "css/position_fixed_scroll.html",
+     [
+      [
+       "/_mozilla/css/position_fixed_scroll_ref.html",
+       "=="
+      ]
+     ],
+     {}
+    ]
+   ],
    "css/position_fixed_simple_a.html": [
     [
      "css/position_fixed_simple_a.html",
@@ -8977,6 +8998,10 @@
    "css/position_fixed_overflow_b.html": [
     []
    ],
+   "css/position_fixed_scroll.html": [],
+   "css/position_fixed_scroll_ref.html": [
+    []
+   ],
    "css/position_fixed_simple_b.html": [
     []
    ],
@@ -11253,6 +11278,7 @@
      {}
     ]
    ],
+   "css/position_fixed_scroll.html": [],
    "css/stylesheet_media_queries.html": [
     [
      "css/stylesheet_media_queries.html",
@@ -12596,6 +12622,12 @@
      {}
     ]
    ]
+  },
+  "visual": {
+   "css/position_fixed_scroll.html": []
+  },
+  "wdspec": {
+   "css/position_fixed_scroll.html": []
   }
  },
  "paths": {
@@ -16959,6 +16991,14 @@
    "a8947566153c187ba3191084f89d0163bc5b666e",
    "support"
   ],
+  "css/position_fixed_scroll.html": [
+   "712265957f2c2ff0102eab09219b44bc5bf7f032",
+   "reftest"
+  ],
+  "css/position_fixed_scroll_ref.html": [
+   "dc2e72a96ac2d82f038605812c79b9f78c1547dd",
+   "support"
+  ],
   "css/position_fixed_simple_a.html": [
    "d01b955091107990d014e7f7be9c1181e5b06d66",
    "reftest"
diff --git a/tests/wpt/mozilla/tests/css/position_fixed_scroll.html b/tests/wpt/mozilla/tests/css/position_fixed_scroll.html
new file mode 100644
index 00000000000..712265957f2
--- /dev/null
+++ b/tests/wpt/mozilla/tests/css/position_fixed_scroll.html
@@ -0,0 +1,17 @@
+<html>
+  <head>
+    <link rel=match href=position_fixed_scroll_ref.html>
+      <style>
+        body {
+            margin: 0;
+        }
+      </style>
+  </head>
+  <body>
+      <div style="height: 100px; width: 100px; background: green; position: fixed;"></div>
+      <div style="height: 5000px;"></div>
+      <script>
+           window.scrollTo(0, 100);
+      </script>
+  </body>
+</html>
diff --git a/tests/wpt/mozilla/tests/css/position_fixed_scroll_ref.html b/tests/wpt/mozilla/tests/css/position_fixed_scroll_ref.html
new file mode 100644
index 00000000000..dc2e72a96ac
--- /dev/null
+++ b/tests/wpt/mozilla/tests/css/position_fixed_scroll_ref.html
@@ -0,0 +1,12 @@
+<html>
+  <head>
+      <style>
+        body {
+            margin: 0;
+        }
+      </style>
+  </head>
+  <body>
+      <div style="height: 100px; width: 100px; background: green;"></div>
+  </body>
+</html>