diff --git a/Cargo.lock b/Cargo.lock
index 0c73f24e5396..e2bd485c5733 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -269,7 +269,7 @@ dependencies = [
  "cssparser 0.23.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.17.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "fnv 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "gleam 0.4.29 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.4.34 (registry+https://github.com/rust-lang/crates.io-index)",
  "ipc-channel 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.1.37 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -330,7 +330,7 @@ name = "cgl"
 version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "gleam 0.4.29 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.4.34 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.39 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -418,7 +418,7 @@ version = "0.0.1"
 dependencies = [
  "euclid 0.17.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "gfx_traits 0.0.1",
- "gleam 0.4.29 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.4.34 (registry+https://github.com/rust-lang/crates.io-index)",
  "image 0.18.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "ipc-channel 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.39 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1081,7 +1081,7 @@ dependencies = [
 
 [[package]]
 name = "gleam"
-version = "0.4.29"
+version = "0.4.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "gl_generator 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1307,7 +1307,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "cgl 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "core-foundation 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "gleam 0.4.29 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.4.34 (registry+https://github.com/rust-lang/crates.io-index)",
  "leaky-cow 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.39 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -1559,7 +1559,7 @@ dependencies = [
  "euclid 0.17.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "gaol 0.0.1 (git+https://github.com/servo/gaol)",
  "gfx 0.0.1",
- "gleam 0.4.29 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.4.34 (registry+https://github.com/rust-lang/crates.io-index)",
  "ipc-channel 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "layout_thread 0.0.1",
  "log 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2051,7 +2051,7 @@ dependencies = [
  "core-foundation 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.17.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "gl_generator 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "gleam 0.4.29 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.4.34 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libloading 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2497,7 +2497,7 @@ dependencies = [
  "encoding_rs 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.17.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "fnv 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "gleam 0.4.29 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.4.34 (registry+https://github.com/rust-lang/crates.io-index)",
  "half 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "html5ever 0.22.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper 0.10.13 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2717,7 +2717,7 @@ dependencies = [
  "bitflags 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.17.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "gdi32-sys 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "gleam 0.4.29 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.4.34 (registry+https://github.com/rust-lang/crates.io-index)",
  "glutin 0.13.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "libservo 0.0.1",
  "log 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2778,7 +2778,7 @@ dependencies = [
  "cmake 0.1.29 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.17.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "expat-sys 2.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "gleam 0.4.29 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.4.34 (registry+https://github.com/rust-lang/crates.io-index)",
  "glutin 0.13.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "glx 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "io-surface 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3547,7 +3547,7 @@ dependencies = [
  "euclid 0.17.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "freetype 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "fxhash 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "gleam 0.4.29 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gleam 0.4.34 (registry+https://github.com/rust-lang/crates.io-index)",
  "image 0.18.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3869,7 +3869,7 @@ dependencies = [
 "checksum getopts 0.2.14 (registry+https://github.com/rust-lang/crates.io-index)" = "d9047cfbd08a437050b363d35ef160452c5fe8ea5187ae0a624708c91581d685"
 "checksum gif 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "8a80d6fe9e52f637df9afd4779449a7be17c39cc9c35b01589bb833f956ba596"
 "checksum gl_generator 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7a795170cbd85b5a7baa58d6d7525cae6a03e486859860c220f7ebbbdd379d0a"
-"checksum gleam 0.4.29 (registry+https://github.com/rust-lang/crates.io-index)" = "b74def65dc2902b459fc7dd258b10695130408b79fd8f8beb59f475b1536ed81"
+"checksum gleam 0.4.34 (registry+https://github.com/rust-lang/crates.io-index)" = "b4e5e2cdcadecdf3886e7808b6a38eae0a48dfe98c5c12b776fc861b80edf4a2"
 "checksum glob 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "8be18de09a56b60ed0edf84bc9df007e30040691af7acd1c41874faac5895bfb"
 "checksum glutin 0.13.1 (registry+https://github.com/rust-lang/crates.io-index)" = "90de8e0391e57098acfbfe693b23065e9186255d370ebae12c933b7d77df8424"
 "checksum glx 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "63a6e7c2846e12626455f45ebaff9d92161436dd0fa703d9d198012e528ca7b9"
diff --git a/components/canvas/Cargo.toml b/components/canvas/Cargo.toml
index b673e430da9b..b03c016ea383 100644
--- a/components/canvas/Cargo.toml
+++ b/components/canvas/Cargo.toml
@@ -16,7 +16,7 @@ compositing = {path = "../compositing"}
 cssparser = "0.23.0"
 euclid = "0.17"
 fnv = "1.0"
-gleam = "0.4.29"
+gleam = "0.4.34"
 ipc-channel = "0.10"
 log = "0.4"
 num-traits = "0.1.32"
diff --git a/components/canvas/webgl_thread.rs b/components/canvas/webgl_thread.rs
index 7bcb303bbf1c..247a5a5e52cb 100644
--- a/components/canvas/webgl_thread.rs
+++ b/components/canvas/webgl_thread.rs
@@ -893,8 +893,10 @@ impl WebGLImpl {
                 ctx.gl().delete_vertex_arrays(&[id.get()]),
             WebGLCommand::BindVertexArray(id) =>
                 ctx.gl().bind_vertex_array(id.map_or(0, WebGLVertexArrayId::get)),
-            WebGLCommand::AliasedPointSizeRange(sender) => {
-                sender.send(ctx.gl().alias_point_size_range()).unwrap()
+            WebGLCommand::AliasedPointSizeRange(sender) =>
+                sender.send(ctx.gl().alias_point_size_range()).unwrap(),
+            WebGLCommand::AliasedLineWidthRange(sender) => {
+                sender.send(ctx.gl().alias_line_width_range()).unwrap()
             }
         }
 
diff --git a/components/canvas_traits/webgl.rs b/components/canvas_traits/webgl.rs
index cbb088e710cb..5334d5c0def5 100644
--- a/components/canvas_traits/webgl.rs
+++ b/components/canvas_traits/webgl.rs
@@ -275,6 +275,7 @@ pub enum WebGLCommand {
     DeleteVertexArray(WebGLVertexArrayId),
     BindVertexArray(Option<WebGLVertexArrayId>),
     AliasedPointSizeRange(WebGLSender<(f32, f32)>),
+    AliasedLineWidthRange(WebGLSender<(f32, f32)>),
 }
 
 macro_rules! define_resource_id_struct {
@@ -548,6 +549,7 @@ impl fmt::Debug for WebGLCommand {
             DeleteVertexArray(..) => "DeleteVertexArray",
             BindVertexArray(..) => "BindVertexArray",
             AliasedPointSizeRange(..) => "AliasedPointSizeRange",
+            AliasedLineWidthRange(..) => "AliasedLineWidthRange",
         };
 
         write!(f, "CanvasWebGLMsg::{}(..)", name)
diff --git a/components/compositing/Cargo.toml b/components/compositing/Cargo.toml
index 0948d0f0ae72..7bc4dd296e97 100644
--- a/components/compositing/Cargo.toml
+++ b/components/compositing/Cargo.toml
@@ -13,7 +13,7 @@ path = "lib.rs"
 [dependencies]
 euclid = "0.17"
 gfx_traits = {path = "../gfx_traits"}
-gleam = "0.4.29"
+gleam = "0.4.34"
 image = "0.18"
 ipc-channel = "0.10"
 libc = "0.2"
diff --git a/components/script/Cargo.toml b/components/script/Cargo.toml
index 2b19aea49a69..f8edccd9092f 100644
--- a/components/script/Cargo.toml
+++ b/components/script/Cargo.toml
@@ -45,7 +45,7 @@ domobject_derive = {path = "../domobject_derive"}
 encoding_rs = "0.7"
 euclid = "0.17"
 fnv = "1.0"
-gleam = "0.4.29"
+gleam = "0.4.34"
 half = "1.0"
 html5ever = "0.22"
 hyper = "0.10"
diff --git a/components/script/dom/webglrenderingcontext.rs b/components/script/dom/webglrenderingcontext.rs
index ce09fda89433..8e4757a58417 100644
--- a/components/script/dom/webglrenderingcontext.rs
+++ b/components/script/dom/webglrenderingcontext.rs
@@ -1326,6 +1326,14 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
                 [width, height].to_jsval(cx, rval.handle_mut());
                 return rval.get();
             }
+            constants::ALIASED_LINE_WIDTH_RANGE => {
+                let (sender, receiver) = webgl_channel().unwrap();
+                self.send_command(WebGLCommand::AliasedLineWidthRange(sender));
+                let (width, height) = receiver.recv().unwrap();
+                rooted!(in(cx) let mut rval = UndefinedValue());
+                [width, height].to_jsval(cx, rval.handle_mut());
+                return rval.get();
+            }
             _ => {
                 if !self.extension_manager.is_get_parameter_name_enabled(parameter) {
                     self.webgl_error(WebGLError::InvalidEnum);
diff --git a/components/servo/Cargo.toml b/components/servo/Cargo.toml
index 82f3188dade9..b2a28d58da19 100644
--- a/components/servo/Cargo.toml
+++ b/components/servo/Cargo.toml
@@ -40,7 +40,7 @@ devtools_traits = {path = "../devtools_traits"}
 env_logger = "0.5"
 euclid = "0.17"
 gfx = {path = "../gfx"}
-gleam = "0.4.29"
+gleam = "0.4.34"
 ipc-channel = "0.10"
 layout_thread = {path = "../layout_thread"}
 log = "0.4"
diff --git a/ports/servo/Cargo.toml b/ports/servo/Cargo.toml
index d81a005358cb..7bda51c5b388 100644
--- a/ports/servo/Cargo.toml
+++ b/ports/servo/Cargo.toml
@@ -37,7 +37,7 @@ unstable = ["libservo/unstable"]
 backtrace = "0.3"
 bitflags = "1.0"
 euclid = "0.17"
-gleam = "0.4.29"
+gleam = "0.4.34"
 glutin = "0.13"
 libservo = {path = "../../components/servo"}
 log = "0.4"
diff --git a/tests/wpt/mozilla/meta/webgl/conformance-1.0.3/conformance/more/conformance/quickCheckAPI-L_S.html.ini b/tests/wpt/mozilla/meta/webgl/conformance-1.0.3/conformance/more/conformance/quickCheckAPI-L_S.html.ini
deleted file mode 100644
index 098750fdb2c3..000000000000
--- a/tests/wpt/mozilla/meta/webgl/conformance-1.0.3/conformance/more/conformance/quickCheckAPI-L_S.html.ini
+++ /dev/null
@@ -1,5 +0,0 @@
-[quickCheckAPI-L_S.html]
-  type: testharness
-  [WebGL test #0: testValidArgs]
-    expected: FAIL
-