--- a/python/mozbuild/mozbuild/mach_commands.py
+++ b/python/mozbuild/mozbuild/mach_commands.py
@@ -1858,18 +1858,20 @@ class PackageFrontend(MachCommandBase):
                                 break
                             except Exception:
                                 pass
                 for algorithm, digest in (data.get('artifacts', {})
                                               .get(artifact_name, {}).items()):
                     pass
 
                 name = os.path.basename(artifact_name)
+                artifact_url = get_artifact_url(task_id, artifact_name,
+                    use_proxy=not artifact_name.startswith('public/'))
                 super(ArtifactRecord, self).__init__(
-                    get_artifact_url(task_id, artifact_name), name,
+                    artifact_url, name,
                     None, digest, algorithm, unpack=True)
 
         records = OrderedDict()
         downloaded = []
 
         if tooltool_manifest:
             manifest = open_manifest(tooltool_manifest)
             for record in manifest.file_records: