diff --git a/climax/main/downscale_train.py b/climax/main/downscale_train.py
index 55709c5f3c99a9413c48dc9049f296ddc2a5c2d0..ca4ea19c8a2b9df91ef1f1cd3213eb7db33ff205 100644
--- a/climax/main/downscale_train.py
+++ b/climax/main/downscale_train.py
@@ -143,7 +143,7 @@ if __name__ == '__main__':
 
         # define number of output fields
         # check whether modelling pr with probabilistic approach
-        outputs = (Obs_ds.data_vars)
+        outputs = len(Obs_ds.data_vars)
         if PREDICTAND == 'pr' and isinstance(LOSS, BernoulliGammaLoss):
             outputs = 3