diff --git a/Cargo.lock b/Cargo.lock
index 57a4a104ec2c..f61bc940910d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3101,6 +3101,7 @@ dependencies = [
  "geckoservo 0.0.1",
  "libc 0.2.23 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "selectors 0.19.0",
  "size_of_test 0.0.1",
  "style 0.0.1",
diff --git a/tests/unit/stylo/Cargo.toml b/tests/unit/stylo/Cargo.toml
index 21eab2958a18..bae75a35ee18 100644
--- a/tests/unit/stylo/Cargo.toml
+++ b/tests/unit/stylo/Cargo.toml
@@ -26,3 +26,6 @@ selectors = {path = "../../../components/selectors", features = ["gecko_like_typ
 size_of_test = {path = "../../../components/size_of_test"}
 style_traits = {path = "../../../components/style_traits"}
 style = {path = "../../../components/style", features = ["gecko"]}
+
+[build-dependencies]
+regex = "0.2"
diff --git a/tests/unit/stylo/build.rs b/tests/unit/stylo/build.rs
index 111da70f57e0..340d63741a76 100644
--- a/tests/unit/stylo/build.rs
+++ b/tests/unit/stylo/build.rs
@@ -2,24 +2,67 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+extern crate regex;
+
+use regex::Regex;
 use std::env;
-use std::fs;
-use std::io::Write;
-use std::path;
-use std::process::Command;
+use std::fs::File;
+use std::io::{BufRead, BufReader, Write};
+use std::path::Path;
 
 fn main() {
+    let root_path = Path::new("../../../");
+    let bindings_file = root_path.join("components/style/gecko/generated/bindings.rs");
+    let glue_file = root_path.join("ports/geckolib/glue.rs");
+
     println!("cargo:rerun-if-changed=build.rs");
-    println!("cargo:rerun-if-changed=check_bindings.py");
-    println!("cargo:rerun-if-changed=../../../ports/geckolib/glue.rs");
-    println!("cargo:rerun-if-changed=../../../components/style/gecko_bindings/bindings.rs");
-    assert!(Command::new("python").arg("./check_bindings.py")
-                                  .spawn().unwrap().wait().unwrap().success());
+    println!("cargo:rerun-if-changed={}", glue_file.display());
+    println!("cargo:rerun-if-changed={}", bindings_file.display());
+
+    let env_out_dir = env::var("OUT_DIR").unwrap();
+    let out_dir = Path::new(&env_out_dir);
+
+    {
+        let output = out_dir.join("check_bindings.rs");
+        let r = BufReader::new(File::open(bindings_file).unwrap());
+        let mut w = File::create(output).unwrap();
+
+        w.write_all(b"fn assert_types() {\n").unwrap();
+
+        let matcher = Regex::new(r"fn\s*Servo_([a-zA-Z0-9_]+)\s*\(").unwrap();
+
+        for line in r.lines() {
+            let s = line.unwrap();
+            for cap in matcher.captures_iter(&s) {
+                // GetStyleVariables is a Servo_* function, but temporarily defined
+                // on the Gecko side.
+                if &cap[1] != "GetStyleVariables" {
+                    w.write_all(format!("    [ Servo_{0}, bindings::Servo_{0} ];\n", &cap[1]).as_bytes()).unwrap();
+                }
+            }
+        }
+
+        w.write_all(b"}\n").unwrap();
+    }
+
+    {
+        let output = out_dir.join("glue.rs");
+        let r = BufReader::new(File::open(glue_file).unwrap());
+        let mut w = File::create(output).unwrap();
+
+        w.write_all(b"pub use style::gecko::arc_types::*;\n").unwrap();
+
+        for line in r.lines() {
+            let s = line.unwrap().replace("pub extern \"C\" fn", "pub unsafe extern \"C\" fn");
+            w.write_all(s.as_bytes()).unwrap();
+            w.write_all(b"\n").unwrap();
+        }
+    }
 
     // https://github.com/rust-lang/cargo/issues/3544
     let style_out_dir = env::var_os("DEP_FOR SOME REASON THE LINKS KEY IS REQUIRED \
                                      TO PASS DATA AROUND BETWEEN BUILD SCRIPTS_OUT_DIR").unwrap();
-    fs::File::create(path::PathBuf::from(env::var_os("OUT_DIR").unwrap()).join("bindings.rs"))
+    File::create(out_dir.join("bindings.rs"))
         .unwrap()
         .write_all(format!("include!(concat!({:?}, \"/gecko/structs_debug.rs\"));",
                            style_out_dir).as_bytes())
diff --git a/tests/unit/stylo/check_bindings.py b/tests/unit/stylo/check_bindings.py
deleted file mode 100755
index b337aa7665aa..000000000000
--- a/tests/unit/stylo/check_bindings.py
+++ /dev/null
@@ -1,35 +0,0 @@
-#!/usr/bin/env python
-
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-import os
-import re
-
-ROOT_PATH = os.path.join("..", "..", "..")
-INPUT_FILE = os.path.join(ROOT_PATH, "components", "style", "gecko", "generated", "bindings.rs")
-OUTPUT_FILE = os.path.join(os.environ["OUT_DIR"], "check_bindings.rs")
-GLUE_FILE = os.path.join(ROOT_PATH, "ports", "geckolib", "glue.rs")
-GLUE_OUTPUT_FILE = os.path.join(os.environ["OUT_DIR"], "glue.rs")
-
-TEMPLATE = """\
-    [ Servo_{name}, bindings::Servo_{name} ];
-"""
-
-with open(INPUT_FILE, "r") as bindings, open(OUTPUT_FILE, "w+") as tests:
-    tests.write("fn assert_types() {\n")
-
-    pattern = re.compile("fn\s*Servo_([a-zA-Z0-9_]+)\s*\(")
-
-    for line in bindings:
-        match = pattern.search(line)
-        if match:
-            tests.write(TEMPLATE.format(name=match.group(1)))
-
-    tests.write("}\n")
-
-with open(GLUE_FILE, "r") as glue, open(GLUE_OUTPUT_FILE, "w+") as glue_output:
-    glue_output.write("pub use style::gecko::arc_types::*;")
-    for line in glue:
-        glue_output.write(line.replace("pub extern \"C\" fn", "pub unsafe extern \"C\" fn"))