diff --git a/backend/open_webui/utils/auth.py b/backend/open_webui/utils/auth.py
index 280666ff0..c55a8e2c1 100644
--- a/backend/open_webui/utils/auth.py
+++ b/backend/open_webui/utils/auth.py
@@ -143,8 +143,14 @@ def get_license_data(app, key):
             pn, pt = nt(pb)
 
             data = json.loads(aesgcm.decrypt(pn, pt, None).decode())
-            if not data.get('exp') or data.get('exp') < datetime.now().date():
-                return False
+
+            exp = data.get('exp')
+            if exp:
+                if isinstance(exp, str):
+                    from datetime import date
+                    exp = date.fromisoformat(exp)
+                if exp < datetime.now().date():
+                    return False
 
             data_handler(data)
             return True