--- a/taskcluster/taskgraph/transforms/repackage_signing.py
+++ b/taskcluster/taskgraph/transforms/repackage_signing.py
@@ -110,16 +110,23 @@ def make_repackage_signing_description(c
                        'upstream-artifacts': upstream_artifacts,
                        'max-run-time': 3600},
             'scopes': scopes,
             'dependencies': dependencies,
             'attributes': attributes,
             'run-on-projects': dep_job.attributes.get('run_on_projects'),
             'treeherder': treeherder,
         }
-        if 'macosx' in dep_job.attributes.get('build_platform'):
+
+        funsize_platforms = [
+            'macosx64-nightly',
+            'win32-nightly',
+            'win64-nightly'
+        ]
+        if dep_job.attributes.get('build_platform') in funsize_platforms and \
+                dep_job.attributes.get('nightly'):
             route_template = "project.releng.funsize.level-{level}.{project}"
             task['routes'] = [
                 route_template.format(project=config.params['project'],
                                       level=config.params['level'])
             ]
 
         yield task