diff --git a/Cargo.lock b/Cargo.lock
index 28c73cbceda..d9da141d72e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -394,7 +394,7 @@ dependencies = [
  "azure 0.36.0 (git+https://github.com/servo/rust-azure)",
  "byteorder 1.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "canvas_traits 0.0.1",
- "cssparser 0.25.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cssparser 0.25.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.19.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "gleam 0.6.18 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -416,7 +416,7 @@ dependencies = [
 name = "canvas_traits"
 version = "0.0.1"
 dependencies = [
- "cssparser 0.25.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cssparser 0.25.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.19.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "gleam 0.6.18 (registry+https://github.com/rust-lang/crates.io-index)",
  "ipc-channel 0.11.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -812,7 +812,7 @@ dependencies = [
 
 [[package]]
 name = "cssparser"
-version = "0.25.5"
+version = "0.25.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "cssparser-macros 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2671,7 +2671,7 @@ version = "0.0.1"
 dependencies = [
  "app_units 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "crossbeam-channel 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "cssparser 0.25.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cssparser 0.25.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.19.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "hashglobe 0.1.0",
  "hyper 0.12.14 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3846,7 +3846,7 @@ dependencies = [
  "cmake 0.1.40 (git+https://github.com/alexcrichton/cmake-rs)",
  "cookie 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "crossbeam-channel 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "cssparser 0.25.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cssparser 0.25.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "deny_public_fields 0.0.1",
  "devtools_traits 0.0.1",
  "dom_struct 0.0.1",
@@ -3933,7 +3933,7 @@ dependencies = [
  "atomic_refcell 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "canvas_traits 0.0.1",
  "crossbeam-channel 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "cssparser 0.25.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cssparser 0.25.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.19.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "gfx_traits 0.0.1",
  "html5ever 0.23.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4021,7 +4021,7 @@ name = "selectors"
 version = "0.21.0"
 dependencies = [
  "bitflags 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "cssparser 0.25.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cssparser 0.25.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "derive_more 0.13.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "fxhash 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4636,7 +4636,7 @@ dependencies = [
  "bitflags 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "byteorder 1.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "crossbeam-channel 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "cssparser 0.25.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cssparser 0.25.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "derive_more 0.13.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "encoding_rs 0.8.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.19.8 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4704,7 +4704,7 @@ version = "0.0.1"
 dependencies = [
  "app_units 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "byteorder 1.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "cssparser 0.25.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cssparser 0.25.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.19.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "html5ever 0.23.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rayon 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4726,7 +4726,7 @@ version = "0.0.1"
 dependencies = [
  "app_units 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "bitflags 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "cssparser 0.25.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cssparser 0.25.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.19.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "malloc_size_of 0.0.1",
@@ -4891,7 +4891,7 @@ dependencies = [
 name = "to_shmem"
 version = "0.0.1"
 dependencies = [
- "cssparser 0.25.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cssparser 0.25.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.88 (registry+https://github.com/rust-lang/crates.io-index)",
  "servo_arc 0.1.1",
  "smallbitvec 2.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -5787,7 +5787,7 @@ dependencies = [
 "checksum crossbeam-utils 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "2760899e32a1d58d5abb31129f8fae5de75220bc2176e77ff7c627ae45c918d9"
 "checksum crossbeam-utils 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "677d453a17e8bd2b913fa38e8b9cf04bcdbb5be790aa294f2389661d72036015"
 "checksum crossbeam-utils 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)" = "f8306fcef4a7b563b76b7dd949ca48f52bc1141aa067d2ea09565f3e2652aa5c"
-"checksum cssparser 0.25.5 (registry+https://github.com/rust-lang/crates.io-index)" = "e06795910fc2f585a75bdc9690fbcc51e83519f07b6eb981db43944643c04933"
+"checksum cssparser 0.25.7 (registry+https://github.com/rust-lang/crates.io-index)" = "a921abc45ea75c2c817d951caeda31b94539d09a6b5e8d58a857b3b35c9c3894"
 "checksum cssparser-macros 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "b16e382d9b983fdb9ac6a36b37fdeb84ce3ea81f749febfee3463cfa7f24275e"
 "checksum cstr 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "19f7a08ed4ecd7e077d4cee63937473e6f7cf57b702a9114ef41751b2cbc0f60"
 "checksum cstr-macros 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "0f12dd847ec773fc98d75edba5394cb87d0f35e7ee548a4c81849ca6374b3d48"
diff --git a/tests/wpt/metadata/css/css-variables/variable-substitution-basic.html.ini b/tests/wpt/metadata/css/css-variables/variable-substitution-basic.html.ini
index 1c44938b30e..bd53e7d9971 100644
--- a/tests/wpt/metadata/css/css-variables/variable-substitution-basic.html.ini
+++ b/tests/wpt/metadata/css/css-variables/variable-substitution-basic.html.ini
@@ -11,6 +11,3 @@
   [Fallback value which is also a variable reference]
     expected: FAIL
 
-  [You can't build up a single token where part of it is provided by a variable (percentages)]
-    expected: FAIL
-