diff --git a/src/config/api-server/vnc_auth_keystone.py b/src/config/api-server/vnc_auth_keystone.py
index b4e15f9c0a5..1fe1e5748dc 100644
--- a/src/config/api-server/vnc_auth_keystone.py
+++ b/src/config/api-server/vnc_auth_keystone.py
@@ -235,8 +235,14 @@ def verify_signed_token(self, user_token):
         try:
             return self._auth_middleware.verify_signed_token(user_token)
         except:
-            return None
-    # end
+            # Retry verify after fetching the certs.
+            try:
+                self._auth_middleware.fetch_signing_cert()
+                self._auth_middleware.fetch_ca_cert()
+                return self._auth_middleware.verify_signed_token(user_token)
+            except:
+                return None
+    # end verify_signed_token
 
     # convert keystone user id to name
     def user_id_to_name(self, id):