diff --git a/etc/ci/update-wpt-checkout b/etc/ci/update-wpt-checkout
index 1ab4b62ec64..5f8ef9d1a15 100755
--- a/etc/ci/update-wpt-checkout
+++ b/etc/ci/update-wpt-checkout
@@ -100,7 +100,7 @@ function unsafe_open_pull_request() {
     git checkout "${BRANCH_NAME}" || return 0
 
     if [[ -z "${WPT_SYNC_TOKEN+set}" && "${TASKCLUSTER_PROXY_URL+set}" == "set" ]]; then
-        SECRET_RESPONSE=$(curl ${TASKCLUSTER_PROXY_URL}/secrets/v1/secret/project/servo/wpt-sync)
+        SECRET_RESPONSE=$(curl ${TASKCLUSTER_PROXY_URL}/api/secrets/v1/secret/project/servo/wpt-sync)
         WPT_SYNC_TOKEN=`echo "${SECRET_RESPONSE}" | jq --raw-output '.secret.token'`
     fi
 
diff --git a/etc/taskcluster/decision_task.py b/etc/taskcluster/decision_task.py
index 358e1af0b3b..6673a89b6ce 100644
--- a/etc/taskcluster/decision_task.py
+++ b/etc/taskcluster/decision_task.py
@@ -238,7 +238,8 @@ def upload_docs():
         .with_scopes("secrets:get:project/servo/doc.servo.org")
         .with_env(PY="""if 1:
             import urllib, json
-            url = "http://taskcluster/secrets/v1/secret/project/servo/doc.servo.org"
+            root_url = os.environ["TASKCLUSTER_PROXY_URL"]
+            url = root_url + "/api/secrets/v1/secret/project/servo/doc.servo.org"
             token = json.load(urllib.urlopen(url))["secret"]["token"]
             open("/root/.git-credentials", "w").write("https://git:%s@github.com/" % token)
         """)
diff --git a/etc/taskcluster/decisionlib.py b/etc/taskcluster/decisionlib.py
index 0436612dafa..6b9d69f89d4 100644
--- a/etc/taskcluster/decisionlib.py
+++ b/etc/taskcluster/decisionlib.py
@@ -57,8 +57,8 @@ class Config:
         self.git_ref = os.environ.get("GIT_REF")
         self.git_sha = os.environ.get("GIT_SHA")
 
-        root_url = os.environ.get("TASKCLUSTER_ROOT_URL")
-        self.legacy_tc_deployment = root_url == "https://taskcluster.net"
+        self.tc_root_url = os.environ.get("TASKCLUSTER_ROOT_URL")
+        self.legacy_tc_deployment = self.tc_root_url == "https://taskcluster.net"
 
         if self.legacy_tc_deployment:
             self.default_provisioner_id = "aws-provisioner-v1"
@@ -99,10 +99,9 @@ class Shared:
         self.now = datetime.datetime.utcnow()
         self.found_or_created_indexed_tasks = {}
 
-        # taskclusterProxy URLs:
-        # https://docs.taskcluster.net/docs/reference/workers/docker-worker/docs/features
-        self.queue_service = taskcluster.Queue(options={"baseUrl": "http://taskcluster/queue/v1/"})
-        self.index_service = taskcluster.Index(options={"baseUrl": "http://taskcluster/index/v1/"})
+        options = {"rootUrl": os.environ["TASKCLUSTER_PROXY_URL"]}
+        self.queue_service = taskcluster.Queue(options)
+        self.index_service = taskcluster.Index(options)
 
     def from_now_json(self, offset):
         """
@@ -621,11 +620,14 @@ class UnixTaskMixin(Task):
         """.format(n=n))
 
     def with_curl_artifact_script(self, task_id, artifact_name, out_directory=""):
+        if CONFIG.legacy_tc_deployment:
+            queue_service = "https://queue.taskcluster.net"
+        else:  # pragma: no cover
+            queue_service = CONFIG.tc_root_url + "/api/queue"
         return self \
         .with_dependencies(task_id) \
         .with_curl_script(
-            "https://queue.taskcluster.net/v1/task/%s/artifacts/public/%s"
-                % (task_id, artifact_name),
+            queue_service + "/v1/task/%s/artifacts/public/%s" % (task_id, artifact_name),
             os.path.join(out_directory, url_basename(artifact_name)),
         )
 
diff --git a/etc/taskcluster/mock.py b/etc/taskcluster/mock.py
index 10fe23b22a1..c0b45e6a1f4 100755
--- a/etc/taskcluster/mock.py
+++ b/etc/taskcluster/mock.py
@@ -45,6 +45,7 @@ sys.dont_write_bytecode = True
 os.environ.update(**{k: k for k in "TASK_ID TASK_OWNER TASK_SOURCE GIT_URL GIT_SHA".split()})
 os.environ["GIT_REF"] = "refs/heads/auto"
 os.environ["TASKCLUSTER_ROOT_URL"] = "https://taskcluster.net"
+os.environ["TASKCLUSTER_PROXY_URL"] = "http://taskcluster"
 import decision_task
 
 print("\n# Push:")
diff --git a/python/servo/package_commands.py b/python/servo/package_commands.py
index 40bbd61b92c..a663763a398 100644
--- a/python/servo/package_commands.py
+++ b/python/servo/package_commands.py
@@ -591,7 +591,7 @@ class PackageCommands(CommandBase):
         def get_taskcluster_secret(name):
             url = (
                 os.environ.get("TASKCLUSTER_PROXY_URL", "http://taskcluster") +
-                "/secrets/v1/secret/project/servo/" +
+                "/api/secrets/v1/secret/project/servo/" +
                 name
             )
             return json.load(urllib.request.urlopen(url))["secret"]