diff --git a/server/portal/apps/auth/models.py b/server/portal/apps/auth/models.py
index a49e85b29..96bcb2e6a 100644
--- a/server/portal/apps/auth/models.py
+++ b/server/portal/apps/auth/models.py
@@ -6,6 +6,7 @@
 from django.conf import settings
 from tapipy.tapis import Tapis
 from django.db import transaction
+from threading import Lock
 
 logger = logging.getLogger(__name__)
 
@@ -81,7 +82,11 @@ def client(self):
         with transaction.atomic():
             if self.expired:
                 try:
-                    client.refresh_tokens()
+                    lock = Lock()
+                    logger.debug("getting lock")
+                    with lock:
+                        logger.debug("refreshing token with lock")
+                        client.refresh_tokens()
                 except Exception:
                     logger.exception('Tapis Token refresh failed')
                     raise