diff --git a/Cargo.lock b/Cargo.lock
index 64d19f1802d..35e2080f928 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3749,7 +3749,7 @@ checksum = "903970ae2f248d7275214cf8f387f8ba0c4ea7e3d87a320e85493db60ce28616"
 [[package]]
 name = "mozjs"
 version = "0.14.1"
-source = "git+https://github.com/servo/mozjs#821687091d68e9f98809a60a9111f6d612c0bdb9"
+source = "git+https://github.com/servo/mozjs#8dcf64e1dd1c362b2af3abb735f100bdff8a627d"
 dependencies = [
  "cc",
  "lazy_static",
@@ -3762,7 +3762,7 @@ dependencies = [
 [[package]]
 name = "mozjs_sys"
 version = "0.68.2"
-source = "git+https://github.com/servo/mozjs#821687091d68e9f98809a60a9111f6d612c0bdb9"
+source = "git+https://github.com/servo/mozjs#8dcf64e1dd1c362b2af3abb735f100bdff8a627d"
 dependencies = [
  "bindgen",
  "cc",
diff --git a/python/servo/command_base.py b/python/servo/command_base.py
index a86f756c76c..449c81bbf3d 100644
--- a/python/servo/command_base.py
+++ b/python/servo/command_base.py
@@ -466,11 +466,6 @@ class CommandBase(object):
 
         effective_target = self.cross_compile_target or servo.platform.host_triple()
         if "msvc" in effective_target:
-            # This environment variable is necessary for building mozjs. It would
-            # be nice to be able to set it in the cargo configuration somehow, but it
-            # is platform-dependent.
-            env["MOZILLA_BUILD"] = path.join(self.msvc_package_dir("moztools"))
-
             # Always build harfbuzz from source
             env["HARFBUZZ_SYS_NO_PKG_CONFIG"] = "true"