--- a/taskcluster/taskgraph/transforms/partials_signing.py
+++ b/taskcluster/taskgraph/transforms/partials_signing.py
@@ -5,27 +5,28 @@
 Transform the partials task into an actual task description.
 """
 from __future__ import absolute_import, print_function, unicode_literals
 
 from taskgraph.transforms.base import TransformSequence
 from taskgraph.util.attributes import copy_attributes_from_dependent_job
 from taskgraph.util.scriptworker import get_signing_cert_scope_per_platform
 from taskgraph.util.partials import get_balrog_platform_name, get_partials_artifacts
+from taskgraph.util.taskcluster import get_artifact_prefix
 
 import logging
 logger = logging.getLogger(__name__)
 
 transforms = TransformSequence()
 
 
-def generate_upstream_artifacts(release_history, platform, locale=None):
-    artifact_prefix = 'public/build'
+def generate_upstream_artifacts(job, release_history, platform, locale=None):
+    artifact_prefix = get_artifact_prefix(job)
     if locale:
-        artifact_prefix = 'public/build/{}'.format(locale)
+        artifact_prefix = '{}/{}'.format(artifact_prefix, locale)
     else:
         locale = 'en-US'
 
     artifacts = get_partials_artifacts(release_history, platform, locale)
 
     upstream_artifacts = [{
         "taskId": {"task-reference": '<partials>'},
         "taskType": 'partials',
@@ -65,17 +66,17 @@ def make_task_description(config, jobs):
         attributes = copy_attributes_from_dependent_job(dep_job)
         locale = dep_job.attributes.get('locale')
         if locale:
             attributes['locale'] = locale
             treeherder['symbol'] = 'ps({})'.format(locale)
 
         balrog_platform = get_balrog_platform_name(dep_th_platform)
         upstream_artifacts = generate_upstream_artifacts(
-            config.params['release_history'], balrog_platform, locale)
+            dep_job, config.params['release_history'], balrog_platform, locale)
 
         build_platform = dep_job.attributes.get('build_platform')
         is_nightly = dep_job.attributes.get('nightly')
         signing_cert_scope = get_signing_cert_scope_per_platform(
             build_platform, is_nightly, config
         )
         scopes = [signing_cert_scope, 'project:releng:signing:format:mar_sha384']
         task = {