diff --git a/climax/core/dataset.py b/climax/core/dataset.py
index 03329bdf5073316e9c76ca544c4f1732d53d264b..0850f0943000beddd818e6e99722b6bbb547dbc3 100644
--- a/climax/core/dataset.py
+++ b/climax/core/dataset.py
@@ -136,7 +136,7 @@ class EoDataset(torch.utils.data.Dataset):
             state_file = '_'.join([state_file, repr(loss).strip('()')])
 
         # add suffix for weight decay values
-        state_file = (''.join([state_file, 'd{:.0e}'.format(decay)]) if decay
+        state_file = ('_'.join([state_file, 'd{:.0e}'.format(decay)]) if decay
                       is not None else state_file)
 
         # add suffix for training with anomalies