diff --git a/onn_core.py b/onn_core.py
index e71118b..e8a948a 100644
--- a/onn_core.py
+++ b/onn_core.py
@@ -1262,9 +1262,10 @@ class SGDR(Learner):
         raise Exception('this should never happen.')
 
     def rate_at(self, epoch):
+        base_rate = self.start_rate if self.start_rate is not None else self.optim.lr
         restart, sub_epoch, next_restart = self.split_num(max(1, epoch))
         x = _f(sub_epoch - 1) / _f(next_restart)
-        return self.start_rate * self.decay**_f(restart) * cosmod(x)
+        return base_rate * self.decay**_f(restart) * cosmod(x)
 
     def next(self):
         if not super().next():