diff --git a/Cargo.lock b/Cargo.lock
index 217bc8c7dec..0e78cc72317 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3352,7 +3352,7 @@ dependencies = [
 [[package]]
 name = "webrender"
 version = "0.40.0"
-source = "git+https://github.com/servo/webrender#b2614e4eb58f9dee08b8c38f96bc3bac834c837b"
+source = "git+https://github.com/servo/webrender#caec344131e53c13b022feedbf9d5e04054232c3"
 dependencies = [
  "app_units 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "bincode 1.0.0-alpha6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3381,7 +3381,7 @@ dependencies = [
 [[package]]
 name = "webrender_traits"
 version = "0.40.0"
-source = "git+https://github.com/servo/webrender#b2614e4eb58f9dee08b8c38f96bc3bac834c837b"
+source = "git+https://github.com/servo/webrender#caec344131e53c13b022feedbf9d5e04054232c3"
 dependencies = [
  "app_units 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "bincode 1.0.0-alpha6 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index 05fe2bf665b..8ea37343341 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -22738,11 +22738,11 @@
    "support"
   ],
   "css/multiple_backgrounds.html": [
-   "fef5a64b3dfe66ba69c6f49a80ac6ac0b8099278",
+   "6ca8f5d4383f10b14446462071932e31d7de1aa4",
    "reftest"
   ],
   "css/multiple_backgrounds_ref.html": [
-   "9a2f39aaa51a30f510cf7ced78a3b704126a09f5",
+   "a218179031b80f724d23fbcca9eb9f56c5f773fc",
    "support"
   ],
   "css/multiple_css_class_a.html": [
diff --git a/tests/wpt/mozilla/tests/css/multiple_backgrounds.html b/tests/wpt/mozilla/tests/css/multiple_backgrounds.html
index 29922d60454..ae1cf263a7b 100644
--- a/tests/wpt/mozilla/tests/css/multiple_backgrounds.html
+++ b/tests/wpt/mozilla/tests/css/multiple_backgrounds.html
@@ -18,8 +18,8 @@
         #multibg {
             width: 700px;
             height: 400px;
-            background: url(rust-logo-256x256.png) no-repeat bottom right / 256px 256px,
-                        url(bubbles.png) no-repeat left / 700px 100%,
+            background: url("rust-logo-256x256.png") no-repeat bottom right / 256px 256px,
+                        url("bubbles.png?pipe=trickle(d1)") no-repeat left / 700px 100%,
                         linear-gradient(to right, rgba(30, 75, 115, 1), rgba(255, 255, 255, 0)) no-repeat;
         }
     </style>
diff --git a/tests/wpt/mozilla/tests/css/multiple_backgrounds_ref.html b/tests/wpt/mozilla/tests/css/multiple_backgrounds_ref.html
index 7ff13a4ce18..2783dcb84db 100644
--- a/tests/wpt/mozilla/tests/css/multiple_backgrounds_ref.html
+++ b/tests/wpt/mozilla/tests/css/multiple_backgrounds_ref.html
@@ -22,13 +22,13 @@
         #bubblesbg {
             width: 100%;
             height: 100%;
-            background: url(bubbles.png) no-repeat left / 700px 100%;
+            background: url("bubbles.png?pipe=trickle(d1)") no-repeat left / 700px 100%;
             position: relative;
         }
         #rustbg {
             width: 256px;
             height: 256px;
-            background: url(rust-logo-256x256.png) no-repeat left / 256px 256px;
+            background: url("rust-logo-256x256.png") no-repeat left / 256px 256px;
             position: absolute;
             bottom: 0;
             right: 0;