diff --git a/python/servo/package_commands.py b/python/servo/package_commands.py
index 8ff1170872d..12ab0607a3a 100644
--- a/python/servo/package_commands.py
+++ b/python/servo/package_commands.py
@@ -546,7 +546,11 @@ class PackageCommands(CommandBase):
         import boto3
 
         def get_taskcluster_secret(name):
-            url = os.environ["TASKCLUSTER_PROXY_URL"] + "/secrets/v1/secret/project/servo/" + name
+            url = (
+                os.environ.get("TASKCLUSTER_PROXY_URL", "http://taskcluster") +
+                "/secrets/v1/secret/project/servo/" +
+                name
+            )
             return json.load(urllib.urlopen(url))["secret"]
 
         def get_s3_secret():